A lot will be said with BC's next move. If Bargs is traded and we have to take on a useless, bad salary, we are in the selling hope or false hope cycle. BC will have fans believing we are a good team...just one or two moves from something special, but basically incapable of actually making such a move and taking that next step. If it brings back something the team needs...say a vet with real championship experience, like Pau, or a vet with almost as much experience, but more upside, like Millsap...or relieves capspace (both Pau and Millsap do that, as I'd be ok with Pau's bloated contract for only a season), and if it doesn't bring back a useful player, minimum a 1st rd pick without also tacking on a terrible salary....then we might be on the path to actually winning.
In my mind, there is actually only one logical reason to make this trade: BC believes Ross and JV will be very special, and that Gay won't decline for another 6-7 years. He wants them to build chemistry and still convince Gay to re-sign as a 2nd or 3rd option for something like $8-10 mill a year...BC knows this sacrifices any chance to build on the current team, but believes this team will struggle to add a significant FA (which is fair, because FA is a crapshoot....usually best reserved for rounding out a roster than building a core), that we'd still be at least mediocre enough without Gay to not have a chance at a high/top lottery pick, and so believes the next chance to re-model is in 3 years or so, anyway, when they'll be deciding what to do with JV and Ross, and clearing money.
Basically, this deal works if Bargs is turned into anything useful, and anything other than another bad contract. And it works if it convinces Gay to be a stay for less money when he's up for a new deal...If Ross and JV are potential all-stars, and frankly I could see either one being a better all around player than Gay relative to position, they are the future, but the future of the team has to look good for them to want to stay.