Vince McMahon's org. just made the historic announcement Wednesday afternoon ... saying the ex-Pats superstar will be the face of the event from the WWE Performance Center in Florida.

The event is slated to go down April 4 and 5 -- on closed sets in multiple locations -- thanks to the coronavirus pandemic.

As we previously reported, Gronk finalized a deal with WWE in a "part-time, cameo" type of setting last week ... with ProWrestlingSheet's Ryan Satin initially breaking the news Gronk was close to a deal.

Of course, there's gonna be a different feel to the huge event this year ... with the original plan in Tampa scrapped for a live-streamed event at WWE headquarters with ZERO fans.

A rep for WWE told us at the time, "Only essential personnel will be on the closed set at WWE’s training facility in Orlando, Florida to produce WrestleMania."