Obviously there are numerous hurdles to overcome. Scheduling, PA is a great call out, and just how "NBA vs European league" these teams will be. Like will they still be in another league? I assumed they'd be stand alone. We really don't have much information.
However I also don't think they'll overlap with the NBA so much that you'd see transactions between NBA and NBA-Euro teams.
The $500m price tag is the best indicator. That's just 10% of the avg NBA franchise value. That doesn't get you the rights to NBA level talent.
I'm purely speculating, but I do think it could eventually lead to playing some games against NBA teams. But the easiest format is the least logical and meaningful, which would be NBA champ vs Euro Champ. I don't think we'd see that, or at least nothing more than exhibition game value. Like the Euro champ gains the rights to host the NBA champs in an exhibition game which would be $ value but not credibility value.