I don't know if the developers of the game did this on purpose or not. Perhaps they envisioned a version of the Gaunt family from a time when their name and reputation still had weight, but if you do the simple math of when Hogwarts Legacy actually takes place, 1890, it forces you to realize a few important details about Ominis Gaunt as a character:
The most important detail is that he would be an immediate contemporary of Marvolo Gaunt, the grandfather of Lord Voldemort; very likely his own brother, or perhaps a first cousin, but we know for sure that they were alive at the same time and would have known each other. This is very interesting to me, first of all, because Ominis is presented in the game with a very aristocratic presentation in both his speech and his appearance, not to mention his tendency to drop his family's name as leverage. However, Dumbledore very explicitly states in HBP that the Gaunts had squandered their fortune generations before Marvolo was even born, which applies by extension to Ominis, who would be well aware of this fact. That means that his high-born persona is in fact a thin veneer masking a quickly decaying household.
Second of all, the chapter "House of Gaunt" in Half-Blood Prince provides a lot of immediate context and a demonstration as to the kind of family life Ominis would have had, not as an abstract concept of the family's future, but his actual reality. He might not have been living in squalor yet, but if the behavior of Marvolo and Morfin are anything to go on, saying his family was obsessed with blood status is an understatement, to put it lightly. If you found his introduction where he expresses resentment toward Salazar Slytherin to be a bit heavy-handed or out of place for the time period, as I have seen some suggest, then consider this: Whether or not Slytherin himself was really a maniac obsessed with pure-bloods or if there was more nuance to him makes no difference to Ominis because the Gaunts were this to the absolute extreme, and their connection to their ancestor would come up every time they chose to torture him with the Cruciatus Curse, so to him, Salazar Slytherin is essentially the cause of his trauma and suffering. If anything, you don't actually hear a huge amount of pure-blood fanaticism within the game at all. Ominis could in this context be one of the first individuals to sound the alarm as someone who has seen first-hand what that kind of obsession will often lead to.
Thirdly, and this is something I wish we could actually see in the sequel, is the understanding that Ominis more likely than not would not have survived his family. It is very easy to imagine that someone like Marvolo would not take kindly at all to a person he perceives as an embarrassment to his family name, and we know from the book that by the time Bob Ogden comes to arrest Morfin, he, Marvolo, and Merope are the only descendants left of Slytherin. If a blind relative roughly the same age as Dumbledore was around during this time, Dumbledore would have known about it, since they would have attended school at the same time during Ominis's seventh year.
For these reasons, it would be very interesting and personal for Marvolo to be at least a villain in the next game, if not the primary antagonist, as a looming threat over Ominis. It would tie in perfectly with the book lore, even if the developers didn't fully intend to write it this way. If they did, bravo! If not, then they accidentally struck gold with this potential. This is my full post, probably identical to what I've already shared, but I NEED it to make waves.