Cons: it is now possible to connect microfluidic connections to electrical, or use the wrong sort of couplers, or a bunch of other issues that pose risks to new uses and existing usages of electrical d-sub connections.
Like, imagine if they used regular Edison power cables, or HDMI etc. Sometimes there are good reasons not to use existing standards.
It's similar to many devices having RJ-45 serial console ports, that look like network ports, and if you accidentally connect the wrong cable to it, nothing bad happens.
On the other hand, I could really see hybrid connectors as a solution, i.e. have 4 electrical pins and 5 fluid pins. That way you could have some signalling between the devices and not start pushing fluid through the tubes unless a "correct" device is attached.
If their goal is to make something for clinical applications, having an unexpectedly non-working connection could be a problem. Non-"standard" RJ45 and DB9 connections are notorious for confusing end users.
Edison power cable?