I believe XProtectUpdate is part of Apple's security program.
Yes you are correct and it gets updates regularly off the Internet.
Any reason it would be trying to connect to AKAMAI (Akamai Technologies, Inc.) instead of Apple?
AKAMAI is a data distribution service provider that hosts downloads on ISP servers so it's closer to your physical location thus faster rather than straining Apple's servers in Cupertino.
Extra note: If you enabled a alternate DNS service on your computer or router, you need to make sure the alternate DNS has a server in the general location as your ISP server or AKAMAI downloads get routed to a further away server thus your downloads speeds can be drastically slowed.
By the way, softwater is way off base about LittleSnitch, it's good to have Mac users being aware of what is going on with their machines as this is how malware is discovered and the rest of the non-techie side of the Mac community (and Apple) informed of the dangers.
Keep running LittleSnitch, your doing a good thing asking questions, being alert and not remaining a ignorant sheep.