"As far as I have understood, there will be a Brexit in March 2019 in any event, right?"
That's the line of the UK government. However the EU have now given a ruling that the UK could unilaterally decide not to leave. In other words they are allowing us a way out. As it seems to be clear that if we do go it's either May's Deal (shit) or No Deal (shitter) and the polls suggest that there is now a majority of the country against Brexit (though polls have been very wrong on this issue before) then a brave UK leader could do the right thing and prevent Brexit.
In short, the answer to your question is "No".
But sadly we lack the leadership to prevent it so probably there will be. A few days ago there seemed a slight hope that it could be prevented, rather than by a brave and clear-sighted leader, by a kind of joint inability to agree anything else. I was hoping for something like
1. May's deal voted down (as it's not "hard" enough for the Brexiteers in parliament)
2. Country left with No Deal or find another solution...
3. ... EU will not renegotiate so the only possible other solution is No Brexit
4. No Deal too "hard" from the non-Brexiteers in parliament to go through as it is
5. To decide between No Deal and No Brexit we have another referendum
6. No Brexit wins, loads of whiny racists cry and the pound rises against the euro making my life much easier (which is the main thing)