My guess…Pelosi will not be running for President in 2020. Speaker is a prominent position that gives great visibility to whoever holds the position. Putting Pelosi as speaker prevents anyone else from leveraging the position into a Presidential challenge.
You link to a website that makes tons of allegations with exactly zero evidence. No sauce at all. If you can link up some proofs to any of those allegations, you've got something. Otherwise, nothing to get excited about.