Now imagine this: your favourite setting/game gets blown up. Oh okey guess I just move forward then to Aos after being grumpy old saltbag for an year. You rebase 90 percent of your models/armies while geedubs keeps ending support for your fantasy armies, hello Bretonnia and Wood elves.
Then you hear that okey they have this small side project coming to squares when you have been preaching for 7-8 years how great round bases are and how easy it is to get in to age of sigmar.
They finally figure it out that, bigger bases are better, you can actually rank models now in unit. But of course it's Gw so they don't want age of sigmar players using their toys, they want you to buy them again on little different sized shaped bases.
(sorry for the salt but all these rumours that you can't use aos bases/models are killing me) Sorry for all the beastmen players of old, basing ungors 20mm->25mm->round 25mm->square 25mm if you want official gw size.