- Macs will take 50% of the laptop/desktop market within 6 years
Not super likely. You're forgetting to factor in Windows PCs in the enterprise and Chromebooks in education.
- Soon, if you want the fastest computer you have to buy a Mac
Apple has a decent lead over Intel, AMD, and other ARM vendors. That won't last forever. They'll have to make less efficient SoC's to compete (as is done in the smartphone space), but they'll eventually get there. We won't, however, see any company doing the kind of vertical integration Apple is doing for a LONG time, if ever.
- If you want a laptop that has the best battery life, you have to buy a Mac
That will be true for a while, but not forever and certainly not for longer than 4 years.
- Apple will release a Macbook SE priced at $700-$750. They couldn't before because cheap Intel chips were too slow.
Doubtful, unless by "Macbook SE" you mean "iPad Air".
- Many iPhone users (50% market share in U.S.), iPad users (65%), and Apple Watch (55%) users bought cheap Costco laptops. Apple can win these customers back with an affordable Macbook.
Apple would much rather get those customers on iPads. Frankly, given the markets being targeted, Apple's strategy isn't bad there.
- AAA gaming will come to Macs. Even the slowest Apple Silicon GPU is as fast as a 1050Ti. Soon, the median GPU in a Mac will be faster than the median gaming PC. Combined with a projected 50% market share, AAA game developers can't ignore Macs. Apple will take a cut of every AAA game sale because they will have to go through the App Store just like how they have to go through Steam on Windows.
Just because the M1's graphics capability is impressive doesn't mean that you're going to get AAA titles ported over. It's HARDER to port things over to Apple's GPUs than it is to merely port a Windows game to the Intel version of macOS (as at least GPUs are designed the same way on Intel Macs as they are on PCs). The SoCs in both tvOS-based versions of the Apple TV are more than capable of delivering "console class graphics", but tvOS hasn't, at all, taken off as a living room video gaming platform, despite it being open to developers to develop AAA games for it. You're going to see similar difficulties with Apple Silicon Macs as well.
- By increasing their laptop/desktop share, Apple will sell more Apple One+ subscriptions because they're adding one more major device to the customer's ecosystem.
Eh...Apple One is mostly beneficial on the other platforms. I don't see the Mac bringing Apple anywhere near as many new Apple One subscribers as I do the Apple TV, iPhones, and iPads.
Apple is no longer a brand just for the wealthy. Apple is destroying the low mid-end market with SE products that are simply better than the competition. A $400 iPhone SE is faster than any Android phone. It's quite likely that a $700 Macbook SE will be faster than any Windows laptop. Apple is gunning for marketshare. And then they want to sell subscriptions to their customers.
Apple won't sell a Mac notebook for $700. At best, they may keep an M1 model on sale after every other Mac is already past it. Like, I could totally see the M1 Air, M1 mini, or M1 2-port 13" MacBook Pro lingering around to cater to the low-end market after a better successor version is available, but that's the best you're going to get in terms of a MacBook SE.
Bonus bold predictions: Apple will enter the cloud hardware business and enterprise markets within 10 years. Bloomberg reports that Apple is making a 36 core SoC. Soon, Apple will realize that they can make a better server chip than AMD/Intel. Apple knows that most computing will be done in the cloud in the future. And because Macs will become a dominant laptop/desktop player, Apple will make a huge push into selling more Macs to enterprises and start competing directly with Microsoft there.
Disclosure: I own Apple shares and have bought more since M1 Macs came out.
You have ARM SoCs that are designed and optimized for the enterprise with server hardware, and, on the other end of the spectrum you have ARM SoCs that are designed and optimized for personal computing. Apple's SoCs are on the latter side of that spectrum. Apple could design their 36-core SoC to be somewhere in the middle of that spectrum, but they likely won't. They tried it with Xserve and failed because they didn't know what they were doing (and certainly, once Xserve went from PowerPC to Intel, where the number of rack mounted server options were far more plentiful, there was way less of a need for it).
I do, however believe that Apple SHOULD try to build the next Mac Pro (and Rack-Mounted variants) to be datacenter-capable such that one Mac Pro tower or rack-mounted box can host multiple Mac VDIs for lower-end client systems like MacBook Airs and Mac minis. This is something the Windows and Linux worlds have been able to enjoy for a while now. Certainly Apple could sell thin client variants of the Mac mini and MacBook Air (reducing the cost of both by at least half) that tie into Mac Pro systems used in this fashion (and/or hosted in the cloud). But, I'm not holding my breath. Apple tends to only care about end-user computing and not back-end infrastructure-y things like that.