We cannot know
Brexit or not is determined by EU law and politics and by UK law and politics at the same time.
The European Court of Justice has ruled
The revocation must be decided following a democratic process in accordance with national constitutional requirements. This unequivocal and unconditional decision must be communicated in writing to the European Council.
Such a revocation confirms the EU membership of the Member State concerned under terms that are unchanged as regards its status as a Member State and brings the withdrawal procedure to an end.
Parliament is sovereign, and it cannot constrain its future actions.
- The United Kingdom shall leave the European Union at a set date (currently 29 Mar 2019)
- The United Kingdom shall not accept the deal negotiated with EU27
- The United Kingdom shall not leave the European Union without a deal
These are in order. If later actions by Parliament conflict with earlier ones, the later actions win.
So currently, Parliament has stated "the UK shall not leave the EU without a deal". Any act of Parliament prior to that doesn't contradict it; it contradicts any earlier act.
On the other hand, Parliament has arguably not made an unequivocal and unconditional decision and communicated it to the European Council in writing (that last part is easy; someone can print out the bill and literally walk it over; the first part, less so).
The decision that the UK Parliament made is conditional (on no deal being made), or at least equivocal in its conditionalness.
Or, arguably, the UK has through its democratic process, in accordance with national constitutional requirements, now stated that at the end of March it will have withdrawn from Article 50 if there was no deal in place or extension; at that point, there is remaining condition, and "we won't leave the EU without a deal" is unequivocal.
The meaning of this action could even be decided retroactively: Imagine the day after Brexit, everyone proceeds as if it was a hard Brexit. Borders clank shut, etc.
That very day, Theresa May loses the confidence of the House, she gets replaced by someone whose position is that UK never left the EU due to this resolution, and they convince the ECJ to agree with them.
Or the exact same narrative can occur, except the ECJ could say "no, that isn't how it works, please apply for membership again".
There is no clear answer. This is the realm of politics, optics, and law without precedent.
Words on TV by politicians or pundits could fundamentally change what this action means, long after the action's meaning has seemingly settled.
Enough people state "it is non binding", and that actually makes it less binding. Enough people state "it is binding, Theresa May can no longer legally leave the EU without a deal", and that actually makes it more binding. Because popular interpretation of what was done can sway what it means.