I really don't understand why people say all AM4 users got two or three generations of update. Almost all of the mainstream Zen2 sales since July 2019 where on B450. Many on this very forum suggested B450 motherboards in the build threads themselves since last year,and implied Zen3 would work in it.
People seem to have this weird idea 100% of B450 owners,bought motherboards in May 2018 when Zen+ was launched,so yes they got another generation of upgrade,but 100% of B450 sales were not in 2018. If anything AMD took a lot of its DIY sales share from Intel after Zen2 was launched,which was on top of the Intel CPU shortage woes in late 2018. You can see this with the increasing percentage and ranking of DIY sales from various online stores.
Everything from OEM systems,laptops and many DIY builds. With no B550,unless you were intending to buy a £180+ X570 last year,you were stuck with one generation of updates. This is exactly the same situation with anyone since last July who bought a CFL system,they were stuck with that generation of CPU. The people who did the best were X370 and B350 owners. They went from Zen to Zen2 with double the cores,and big improvements in ST performance.
AMD was on Reddit last July saying it was bad for companies to force motherboard changes. So for 12 months,they knew what was being said regarding Zen3,and even system integrators were not clear on what was happening.
Not just any people,the top people from AMD are active on Reddit and Twitter - this is unlike Intel and Nvidia who are much more hands off. I just question their silence since July 2019 on this.
I honestly hope,AMD learns from this,and clears up anything like this in the future,as quickly as possible. Better then to allow potential truths to snowball out of control.