I always thought it was how odd how poorly Alucard's appearances in CV3 and SotN fit with his appearance in Legends, despite Legends containing some specific references to these two games. That's why I considered the possibly of the developers intending to retroactively reference her in the Sega Saturn port of SotN. However, the other day I thought: "It's almost like the developer of Legends never actually played CV3 or SotN". What if that was actually the case? It may not appear this way because of some of the specific references, but there's actually a good explanation for how this could have happened.
Nineteen ninety-seven was the year IGA created the timeline for use as a reference tool. It's not known how this document actually looked like, but it's possible that aside from just dates, it could have contained brief summaries for each game's story, like
this for example. IGA has been on record saying that he didn't intend to release his timeline at first, but that it later ended up getting leaked anyway. I suspect the developers came up with their idea for Legends' story based on that leaked timeline.
In fact, I suspect they might not even have known Alucard actually appeared in CV3 at all. It's possible the blurb for CV3 in the timeline document just said something like: "Dracula is killed by Trevor Belmont", without specifying the names of the other characters. And later on it maybe said something like: "Alucard, Dracula's son, awakes from a 300-year slumber, blah blah blah." Then the developers read the document and said: "Hey, let's make an origin story to the series and explain why Alucard went into slumber!", without realizing that A) CV3 was already supposed to be the first fight between Dracula and the Belmonts, and B) that SotN's intro already established that Alucard went to sleep after having defeated his father with Trevor.
The above would explain why there's such poor continuity between Legends and CV3/SotN (especially everything involving Alucard), despite the former clearly being intended as a prequel to the latter two.