That doesnt make sense though
Yami BB fights and defeats Ace and then becomes Warlord
He raids ID, gets extra crew, goes to MF, gets Gura
Time skip starts
He then takes on WB territory and wins Payback War
Rocky Port incident happens
Time skip ends
Aokiji is allied with BB (was done during TS but this is latest)
Ten titanic captains confirmed in DR
BBPs raid Baltigo
Wano starts (Reverie is going on I think at same time)
Shanks talks about certain pirate (BB or maybe Loki)
Wano Act 2 happens and we get bounties of Yonkos
BB gets 2.2-2.3 Bil bounty
Wano ends
Post wano we get BB's new bounty of 3.9 Bil
The point is that powerscaling wise it makes no sense for 40 year old BB who got two DFs in MF and everybody saw it to go from 2.2 Bil to 3.9 bil bounty. He already did so much during the TS and pre Wano Act 3 that his power level should be clear for everyone. The Yami teach to Emperor Teach power level was already established when he went from someone hiding behind WB and no known bounty to getting 2.2 Bil direct bounty during or after Reverie.
We saw how Emperors are being made, Luffy gets touted as an Emperor after WCI but we get confirmation that that is not what an Emperor level is, sure he has alliances and achievements but his power level is not enough (BB talks about how it is too soon, Kaido one shots him, Shanks remarks that time of their meeting is coming near meaning Luffy is getting there but hasnt reached the point). We see BB becoming Emperor with his never before seen two DFs (a special Logia and the strongest Paramecia) and beating WBPs and taking over their territory. We see Buggy becoming Yonko because he has Mihawk and Crocodile under him and being seen as Shanks rival.
Luffy gets his bounty as one of three captains to take down the Kaido-BM alliance but he is also the only one of the three to be called a Yonko because he has that bigger resume compared to the other two. To the outside world they only know that SN trio took down BM and Kaido, the details are missing.