Why would apple make a brand new macbook pro and keep all the legacy ports for the limited number of people who really need them.
Keep a single USB A port - people will whinge that they need more because they are a XYZ and couldn't possibly use dongles.
Keep a couple of USB A ports - in a few years everyone will be whinging that all their stuff is USB-C and they only have 2 USB-C ports and one is used for charging. Won't want to buy USB-A -> C connector for same reasons as above.
Do away with them entirely and move to 4 USB-C ports which is future proof and people just buy dongles. Vast majority of people don't use 3 usb devices plugged in at once.
Then put the updated internals into the old macbook pros so people who really really really must have those hdmi, USB-A ports etc can have the latest performance and their ports.
USB-C is becoming more and more ubiquitous and the more devices that use it the cheaper things like docks will be.
I wanted a thunderbolt dock for my 13" macbook pro but didn't ever get one because it would have cost half the value of my laptop for a decent one. Every time I went out and came back I ended up plugging back in:
USB for speakers, power cable, monitor 1 to hdmi, monitor 2 to thunderbolt, ethernet to thunderbolt. I would love to have farmed that off to a dock and just plugged a single cable in.