No one at SE said it was delayed.

There's a miscommunication going around about something Yoshida said in-game at an event that was taken out of context and then spread around on Reddit.

The quote that is being used from Yoshida is "We're a little slow releasing the benchmark. It should be out around the end of May". But the more important thing is the context of the question, which was when the benchmark was being released. And Yoshida explained that it's slower than Stormblood's was. Which could be due to the new races being more complicated, or the fact that we just had a 10-day national holiday stretch here in Japan (likely the latter).

A "delay" implies they had a release date planned/announced that they missed... which is not the case.