You should find (based on similar experience on a Sofia flight) that catering is transferred. Depending on what is available you may find the delay isn't as long as you fear, but then again I'd likely be hoping it'll be 3 hours plus. Flight radar may already know what aircraft is assigned, in which case you can see what it's doing and have a guess at the outcome.

[EDIT] No need, since CIHY has given you chapter and verse.