FWIW I do think it probably is bit of a stunt.
I have the view that DB, even for his (alleged) roving eye, is a pretty decent chap, but is led into various publicity seeking capers by Victoria. This being one.
But I am sure the cause(s) that benefit won't give a toss about that, so who I am I to poo poo it.
By certain accounts, it was VB that pressured him into playing in the US, in order to help her profile.
Now he can finish his career in a reasonably credible league, VB gets some collateral publicity, and causes benefit from that along the way.
Win-Win as I see it.