I was of the same assumption as well. But Dave on his stream said(may be confuse us even more) If Redbull comes and ask for hosting tournament Microsoft would sponsor them immediately. His point being no one approach for hosting or no one trustable that would make a successful tournament approached. This could be true in a sense, as interest parties might have wanted to wait to see how things played out with AoE4 before deciding. But I wonder how did Dave have that information of X people approached and was denied or only Y people approached as opposed to last year. Without these information it would hard to narrow down to the truth.Valid point, that explains prize money distribution after release, also.
Edit: Only exception being Nili offering 100K to himself.