Generic business lesson, not specific to raising funding: you may be occasionally asked to reschedule a meeting on very short notice, sometimes to a time which could not possibly be convenient. This is occasional used as a test: if you say yes, you're communicating that you really want this deal to go through, which means your other options are likely poor. That can then get used against you in negotiations. If, on the other hand, you say "We can't reschedule", you may find that scheduling conflicts resolve themselves as if by magic.
Having a full pipeline gave me leverage to say
n.b. Truthfully conveying to investors/clients/etc that the market circumstances concerning one's availability can quickly change in a fashion against their interests and that as a consequence they should decide quickly does not require any particular state of one's pipeline.