You would think so, but I don't think that Donington enforce it- I did two "quiet" days there this year, both times in the briefing they quite heavily stressed the noise restrictions ,and rules, but on both occasions there were a few bikes that were ridiculously loud , kept expecting them to be pulled, but no they managed to stay out all day.
At Cadwell last month, where I think the limit is generally 102 static, the 790 with Wings can and baffle in was 95Db, H2 with the Akra can with baffle out (and 235 rwhp

) 94 Db
For comparison, my trusty old ZX10 with full Akra evo titanium system used to measure 100/101Db on Cadwell's testers with a Db killer in
As for banning all bikes made after 2000 , I wouldn't be a fan of that , but I do think minimum standard of cleanliness, and un-shonki-ness standards should be enforced - turn up with a dirty/ rusty oily or knackered old shitter, you're not going out!
(I know your comment was tongue in check, but mine isn't- seriously, I do

)