'must be doing sth' used for future time

[joham]

CAMBRIDGE GRAMMAR FOR IELTS says:
We can use may (not), might (not), could (not), must, can't be doing to talk about things possibly happening at a time in the future.

I used to think 'must' can't be used to talk about things possibly happening in the future. Now am I right in making this sentence:
She must be meeting Robert this time tomorrow.

Thank you in advance.

[5jj]

Now am I right in making this sentence:
She must be meeting Robert this time tomorrow.

That sentence is fine with a meaning similar to, "From the evidence we have, it appears that she is meeting Robert...".

It is highly unlikely, though not impossible for must to be used in this utterance with the meaning of obligation.