I know that we're talking too much about subscription, but I wanted to get back to arguments, that this model can become too expensive for hobbyist:
1) as Nocturne said several times, nobody said that there will be subscription at all, and even if - nobody said that Trial or Creator versions will be terminated (first one is free, second one is 39$)
2) subscription might be cheaper in some cases - why? You can only get Windows/Mac version, learn, make a game, and if you want to release it on mobile, you can grab subscription for month or two only, to make adjustments on real devices. So instead of paying 300$ for Windows+Mobile, you might end up in paying 100-150$ (in one year). Still, in both cases it's less than 1$ per day, if you're able to make a game under one year.
3) if there will be something like perpetual license, subscription will become a kind of loan in fact, so that option is much cheaper for hobbyists or those that live in countries which have poor salary
4) you may always pause if you want to take a break, or are waiting for some feature/bugfix . That might again make some savings during one year, compared to one-time license
5) even if there will be any changes, you already have GMS 2.x and I doubt they gonna force anyone to switch into new model, and you gonna keep getting updates for free
So, as for now, no one that wrote a post in this topic will pay even 1$, no matter what changes they gonna made. Nothing to worry about until GMS 3.x comes
I believe that current pricing and subscription can co-exists. If subscription will be ever added, they also need to add something to it, to attract users. For example, priority support queue, maybe possibility to vote for next features, maybe early access, maybe discounts on marketplace. GM/GMS had one-time payment for around 20 years, so I doubt it will vanish completely. I believe that giving us choice will be their choice
Seriously, I should be thankful that they added so many features into GMS 2.x for < 80$ that I paid in November 2016. No other company gave me so many updates for 4+ years for free. (Ok, I bought other exporters later too, but still - they are giving me free updates even after that).