i mean i think this weekly surprise event they announced was because of the problem that we don't get enough MP's even though most of the weapons are like a hundred and upgrade is only 10 MP. That's why they created this type of system even though i don't really like it but i do feel it's kind of fair and not at the same time. But in the end they will eventually change it at some point so we can't judge right now, at least i hope so.

i think it's only when you level up... you can't get mp by simply just playing. Only if you did missions (daily, weekly, etc..)