The word "tanking" is considered impolite in some circles, and so when general managers speak publicly about the cycle of teams trading away veterans and slashing payroll, they'll refer to it as "rebuilding" or "taking a step back." Commissioner Rob Manfred doesn't use the word "tanking" either, probably because that would have implications in any discourse with the MLB Players Association.
But privately, a lot of folks in team management refer to tanking as a matter of course, given how popular the strategy has become since the Astros and Cubs demonstrated how effective it could be under the current rules. Those teams lowered their budgets dramatically, finished near the bottom of the standings repeatedly, picked at or near the top of the draft repeatedly, and won championships -- the Cubs in 2016, the Astros in 2017. Not surprisingly, other teams adopted that system.
However, embracing the idea can turn out to be more difficult than actually carrying it out successfully, especially now that more teams are trying to do the same thing. The Phillies might be the best example of this right now, because whether you want to call what they did "rebuilding" or "tanking," the process hasn't gone as smoothly, or been as successful in the standings as it has for the Astros and Cubs.
