I think you're misremembering what I said about beta and PAX:Guys Simca's prediction so far is correct. He/she knows people so I think beta is gonna be after PAX. Here's how it's gonna go: Beta installer/client going online now but will remain locked. Next week Artcraft and/or Patch notes and the week after PAX actual beta. Simca only said however back in the last week of March that the client could possibly be online during the last week of March and/or the first week of April and he was right.
I believe my prediction is 90% true unless something horribly goes wrong and delays beta even more. Now what I'm wondering is that if the beta client is actually datamined, will Simca release all the info on MMO-C like how he/she did with HotS or not?
PAX is April 11th to April 13th apparently, so yes, if there are no delays and the timeframe I heard a bit ago is accurate, it's possible.
I wouldn't be wildly surprised if it was after PAX instead though, since there aren't any major negative repercussions to being lenient with timeframes that you don't publicize anyway.