The hint works like a dictionary. Should we insist that every dictionary meaning must be applicable in every single sentence, regardless what else is in it? I would hope not.
Words like TO, TOTO, and TAMTO are only plural when the rest of the sentence makes it clear that they refer to plural things or beings:
- Toto je moje nové auto. (This is my new car.)
- Toto jsou moje děti. (These are my children.)
If we just have
- Toto nechceme.
there is nothing to indicate a plural reference, so it needs to be understood as singular.