That is an impossibility. The Yonko are far too pathetic.
Loki > Yonko isn’t really a debate, like Kizaru and Mars, Loki’s mere presence made Luffy shit his pants. Luffy never had any such reaction to any Yonko, not even Saint Shanks.
Here is the thing, Oda has Luffy "reacting'' to Loki and Kizaru to signify to the reader that Admirals are strong and a threat to the Yonko.
Before Luffy became a top tier we already knew that his opponents were strong but now that he became one for the average reader who read Marineford they wouldnt think Admirals are a threat, thus he had Luffy react and says Kizaru is strong to establish that for them.
The same is now done for Loki, Luffy is a top tier and once again he has to specify that Loki is strong for us the readers to scale him.
I hope it makes sense to you and you understand it lol. Not everything is about powerlevels.