Sure.
At the end of the day, is it good or not?
Also depends on what the band was going for with the album. If the goal is to not use anything created before April 1st, 2016, then it's different from say choosing unreleased songs they have written at any point.
Paul Tobias? Are you telling me GN'R fans think Shadow Of Your Love and Back Off Bitch doesn't sound like GN'R with Duff and Slash material? He was writing songs with Axl before GN'R existed...
/jarmo