Selina left for Galar not long after the tournament was officially over, she wanted to start building up an idea and a plan of what her mother and sibling were up to. She knew the basics were that they were looking for pokemon to experiment on and empower the same way Serina Chamcaster, Gileta, Zerina, Chuck's Hibiki and Mike's Mei and Cammt were. 
She assumed her sibling had to have their own pokemon like that now as well. She also needed to know just how deeply rooted in Galar, Nigel operation were.

Of course, Mike's girlfriend Bianca would be their to meet them as would Mei and Cammy so they could find the Lucario tribe to make the cure for the beserker gene.