There is a considerable potential that meeting will not happen: Correção de frase

I would reword it a bit:
Chances are that the meeting won´t happen.

There is a very substantial chance the meeting won't happen as scheduled.

There are substantial chances the meeting won't happen as scheduled. (could also add "...until next month/year, etc".

It´s unlikely that the meeting will happen as scheduled. (...let ' s move the date to November 18 if that is better, is that okay?)

But then, there are other ways to express that. Answering your question, I won´t say "potential" would be wrong, but it sounds like a bit unnatural in English with that context.

I'd go with "There is a great likelihood that the meeting will be called off."