Did you get it from a major distributor or other traceable supplier?
Has it performed as expected?
It was bought from Amazon.com as well. I've never used solder paste before, so I have no baseline by which to compare it. Seems to work fine.
My hunch is that the OP's is genuine as well, for a simple reason: none of the other vendors on Amazon use Fulfillment by Amazon, so it's unlikely Amazon's stock is contaminated with fakes. I also don't think that MG is a brand with enough brand recognition to be on counterfeiters' radar, given that Kester and others are FAR more famous.
I'm guessing that MG wants to expand beyond North America and tasked someone with making new packaging, and they fucked up royally in their cut-and-pasting. Removing English verbiage (CAT NO --> #) would be consistent with internationalization.
A tube of flux gel I bought more recently has a multilingual package insert whose design is somewhere in between the two solder pastes' packaging (scan attached). Both inserts look color laser printed to me, which is entirely reasonable these days.
Their packaging isn't consistent anyway. Their solder wick uses "Cat#".