Presumably, all of those pins on the M.2 connector can be used just as well for generic I/O, and M.2 connectors are cheap, so it may not matter that it was designed for PCIe... you could always use it differently.
You might want to read up on what exactly M.2 connector is, and what kind of signals are available there...
Yup. And their number is pretty limited too (so that would be very limited for all-purpose IOs anyway.)
You'd also have to use an M2 female connector, which implies designing a small PCB if you want to use this board outside of a computer motherboard. (Soldering tiny wires on the connector instead would be crap probably, would be problematic for high-speed stuff, and would be also problematic for the power supply lines. This thing likely draws a lot of current.)
If you want a generic dev board with an Artix-7, go look elsewhere IMHO. QMTECH for instance.
Now of course for those interested in exactly this - a PCIe solution - that should be fun, but without the schematic, probably close to unusable (where are the PCIe signals themselves on the FPGA? a lot of possibilities AFAIK.)
And then, even though XIlinx provides IPs and driver stuff for PCIe development, if you've never done it before, I wouldn't call this easy. A reality check tells me that it WILL end up in a drawer.
But if anyone manages to do anything useful with this board, please report back, that should be interesting!