In the starter packs there are summoners because I found mine of the arcane set all there, I was unlucky not to find any in the last 10 starter packs I opened

Yes foundation cards can be used in modern, the only restriction is that they cannot be used with automations and for that reason, technically, a player who plays in the wild but plays without automations could also use them in the Wild but I don't think there are many human players in the Wild
!PIZZA