I still expect PS5 to outsell PS4.
The combined number of PS + Xbox has remained relatively stable over the last three generations, and now that Xbox's sales are imploding, a lot of Xbone owners who haven't upgraded yet will be getting a PS5 rather than a Series.
PS5 will inherit the vast majority of PS4 owners plus a good many Xbone owners, leading to a larger final total.
I also expect this generation to last longer than the last due to the economic downturn and the rising costs and lengthening time commitment of game development.