I don't believe that's the case. Given the hard cap rules, I think only teams under the cap could have actually claimed Drummond / Aldridge / Griffin and taken on their contracts. And since most of those teams are not competing for a championship, taking on Drummond at $30 million is a massive negative asset that would make no sense for them.
I don't think buyouts are a major issue. Contending teams have the opportunity to add an extra piece that's likely washed and doubtful to swing their championship odds in a meaningful way. But I do think the rules can be adjusted to limit teams to one buyout addition per season and/or include a player's pre-buyout salary on a team's cap sheet.