25th of june is still teh best bet. While 18th is possible, given the that the raid opens 2 weeks after 8.2 it would clash with Independence day holiday from the devs, and they have expressed multiple times how little they enjoy feeling forced to work during a holiday, and a new raid opening will certainly mean a lot of work as all the bugs come to the forefront.
Would be interesting if it came the 18th though, would certainly be the biggest surprise so far.