Mini DP is just a different form factor, the wires are the same. So at the protocol level, there are no reasons whatsoever why this shouldn't work.
At the bare hardware level, the adapter means another contact point, so more opportunities for broken cables and/or bad contacts. Cabling is generally considered critical for DP.
You didn't ask for this but given you're in the planning phase, you probably want to know this:
DP daisy chaining critically depends on each monitor correctly handling Multi-Stream mode. Given that monitors that can do this are just starting to become mass-market ware, this does not always work; for example, early revisions of Dell U2515H are known to be flaky.
The graphics card needs to be powerful enough to shove that many pixels out per second. Moderately powerful GPUs can handle that with ease, but the protocol chips between GPU and connector need to be designed for that load, too.
So: No guarantees at this time, though the situation is going to improve over the next few years as vendors react to complaints. If you order, order from a seller with a full-refunds-no-questions-asked policy.