the reason Alden got the role over Ingruber
This Alden dude is an already established actor who (according to his IMDB bio) Spielberg discovered years ago
The Ingruber guy is a sort of YouTube sensation who lucked into playing young Ford in the Age of Adaline almost like had they looked at a lookalike for hire webpage and casted a Ford lookalike. like a walking FX piece - an alternative to CG deaging
My guess is someone high up said 'no Ingruber' (despite him being the more obvious choice and had done the Adaline movie) .. perhaps they didn't want a sort of media circus about a YouTube lookalike guy getting the role over an established actor? Or didn't want too much an impersonation? (we'll see what happens if they do a Young Indy movie)
interestingly on the IMDB trivia for Solo he isn't mentioned on being on the short list for the role and that the original Lego/Jumps St directors wanted Alden (maybe Ron Howard would've gone with someone else?)