If you need (not want) a phone now, then the choice is clear. A 12 Mini it is - but bear in mind in some locations, they are hard to find - as they weren't exactly flying off the shelves, Apple appears to have lost faith in them. Oddly enough, it seems that Apple consumers - seeking something more 'mobile' - opted more often for the much cheaper SE than the overpriced Mini. Go figure.
That said - and despite the rumour mill - one wonders how enthusiastic Apple is going to be to release another selling failure, especially with some internals being at a sourcing premium. So yeah, there could be a 13 Mini - but if that also includes a spike in storage, bear in mind that could include a spike in price, making it even less desirable for some. Some consumers might just wait for the (also rumoured) 3rd version of the SE, (rumoured) released in the spring.
I just moved to the 12 Mini from an XR with a phone plan coming to an end. Could have waited until September to see what was then promised and wait another month or two before seeing the actual phones, but frankly, there's only so many ways Apple can now reinvent the wheel with their devices and OS, and little of the (rumoured) products I have seen discussed warranted the wait or potential price increase. Upgradability is always an issue, sure - but I put to you many people get rid of their phones before the OS upgrades (seems to be around 5 years) come to an end - so that's just a red herring. Unless Apple has plans of sticking an M1 in a phone with a completely OS file structure, at which point all of our phones are toast.