Nearly all companies will note their right to change components with little or no notice. It does say this right on the bottom of the page on Specialized's website: "Specifications are subject to change without notice." It is possible that Specialized ran out of supply of Altus derailleurs and put a TX800 on it or something (what is the exact model number of the Tourney derailleur on the bike?). In practice, an Altus derailleur isn't that much different from a Tourney in terms of function, weight, or durability. In fact, looking at the picture on Specialized's website closely, the derailleur photographed on the Crossroads 2.0 Step-Through looks like an Altus RD-M280, which is basically a Tourney RD-TX35 with Altus graphics on it. If the Tourney derailleur on the bike is a newer RD-TX800, then you actually have a newer generation derailleur than the Altus RD-M280 that should have come on the bike.

Having said that, I do agree that the lack of a spoke protector indicates that somebody has been into that wheel somehow. Is it even the correct wheel? It should have a 7-speed 12-32 cassette on it. If the wheel appears to be otherwise correct, I would just let it be. You'll see zero difference in function or operation of the bike with this derailleur change. As stated above, you may even have a newer/better derailleur than what should have been on the bike.