That's way to excessive of a leap at this point, especially considering Luffy won't get sole recognition for the downfall of Kaido and Big Mom. Kidd and Law will get partial credit, and depending on what happens with the other Worst Gen members, they might be added to that mix as well. I see Wano being the battle which will basically give rise to the Worst Generations era. If everyone does get an increase after Wano, the max I can see Luffy being at is 2.5-3 Billion.
Remember, we haven't even seen Dragons Bounty yet, which is probably around the same amount of Whitebeard and Roger. Luffy shouldn't be near or above that before it's ever even revealed.