20 ribbons to 19

Ryuubi wrote: »

Theyve said before, that if you get enough ribbons for the "Look at all my ribbons" ribbon, but then lose one, like "Honorable soldier", you'll still keep the "Look" ribbon. And since you got the "Look", youve already been awarded the 5k GP as well. And if you had already spent the 5k, they cant really take it away anymore, now can they?

I have to imagine that this still applies to the M4A1 CC as well. After getting the 20, you get the 21st ribbon, which is the ribbon that awards you with the M4. After its been awarded, its all yours.