>>33734699>kinda cheapens the term legendary to meI can understand the feeling, as it's something that occurred to me too, but it's not something I feel bears out which much thought. Not only are there also other evolving Legendaries in Gen 7, you can catch 2 of them in game and something like upwards of 4 of some of the other Legendaries. These are radically change the presentation of Legendaries in Pokemon. Only the Tapus and the Mythicals really adhere to standard Legendary rules, and they're quickly becoming a small minority of Gen 7's Legendaries.
And it's not like we haven't had artificial Legendaries before. I think it mostly comes down to, for Type: Null, the fact that it's primarily associated with an NPC as their signature mon, you school it in game several times, and its story is inextricably tied to the aforementioned NPC. It's the first time we see a Legend in the making, the Pokedex even explicitly refers to Gladion naming Silvally. That gets it a different feeling than usual, but I don't think it's ultimately a bad one.
I think it's something people will be more comfortable with in time.