Thats the thing.
What if the official boost/all core clock is what AMD have already advertised, that is what everyone on all boards can expect B350 upwards, BUT they are delimited in AGESA on X570/B550 which seem to all have stronger VRM, and run at a higher performance state out the box there...
Look at how much work AMD did with AGESA on RAM control, I'm sure something like the above would NOT be hard for them by comparison. There's also rumours there were AGESA clock locks on the ES 16C part floating around behind the scenes at Computex, again suggesting AMD have controls in place here, either for compatibility, control, or sandbagging reasons.
Not saying its true, not saying it will happen, but there is a distinct level of sense to it; ensure compatibility, whilst offering people a REASON to buy a new board and not just keep an older one...
It'd be also please the motherboard manufacturers, as I am sure some of them can't have been happy buyers dont need a new motherboard each generation like Intel has played in recent years. This could be something else AMD has agreed with them.
Good for AMD as ensures compatibility, good for the motherboard manufacturers as its a way to sell more board upgrades legitimately.
Like I say, this is also theory, but there is a sense to it, that follows with the hand that has already been played with PCI-E 4.0. We will know more soon, either at E3, or on release when final BIOS are released to the masses/reviewers.
This would also be a very clever sandbagging technique, as they've not lied, not at all, just, they've not told us everything yet.