That was quick. The EU has avoided any need for another meeting this month by spelling out the full timetable:

1. When current “deal” is not accepted next week, automatic extension till 12 April which provides only a couple of weeks for actual preparations to minimize damage from automatic “no deal” Brexit on that date.

This is calculated to maximize panic at prospects of crashing out unprepared and thus reduce numbers of Labour MPs from “Leave” constituencies who might have voted for May’s deal.

If the Tory Brexiteers were as stupid as people think it would influence them in the opposite direction by lifting their hopes for “no deal”.

However they already know that “no deal” won’t happen and many are still likely to humiliate themselves by voting for BRINO.

More importantly, it sidelines Corbyn’s waffle about alternative forms of BRINO and ensures rapid agreement on a long delay with participation in the EU elections. Anybody voting against that will be voting to crash out with no preparations so the vote will be overwhelming. This will end up with Brexit supporters in both major parties outvoted at elections centered on the issue of Brexit and will pave the way to referendum even if referendum is not adopted immediately.

2. When UK changes course to put forward new proposals (eg referendum) and decides to participate in European elections before 12 April the EU will offer a long extension.

3. In the highly unlikely event that the UK Parliament accepts the only deal available next week there will be an automatic further extension for actual exit on May 22 to finalize necessary legislation (or run around in panic reversing the decision). European Parliament will then be elected without continuing British obstruction.

Of course above is NOT the way they expressed it. Here is the actual text.

https://uk.reuters.com/article/uk-britain-eu-summit-text-idUKKCN1R22MI

Here is the CNN report of that text:

https://edition.cnn.com/2019/03/21/uk/brexit-delay-theresa-may-eu-gbr-intl/index.html

Here is the Financial Times doing its bit to maintain belief in the absurd idea that May might intend to crash out with no deal.

https://www.ft.com/content/c1bb68fa-4bed-11e9-bbc9-6917dce3dc62

Here’s the Guardian insisting that she was just incompetently drifting rather than “exhausting every alternative” to staying in the EU:

https://www.theguardian.com/politics/2019/mar/21/mays-appeal-falls-flat-as-eu-seizes-control-of-brexit-date

The only thing unclear is whether there will even be time wasted on a third vote to reject the deal, and preliminary vote to allow considering it yet again, given the urgency with which they will have to decide what to do next. My  guess is there will, just to humiliate the maximum number of Tory Brexiteers.