it's not about realism. it's about what was told in the game. expecting coherence and consistency according to the rules of the world in a fantasy setting. for example, Reyna has served the previous god of creation for years before he sacrificed himself. she knows and does what MC likes even before he knows it himself. her service included sexual service. it's not explicitly said, but it's highly likely that her virginity was taken by the previous god. there is still a small chance she could be a virgin, but in that intimate moment with MC, she could have easily mentioned it. it's mostly an inference with available information. the dev might have confirmed her virginity outside of the game, but for now in the game there is nothing. the same way, we can infer that the previous god refused her pregnancy, as she sexually served him for years, she most likely has absorbed a ton of semen and still didn't have a child. elf fertility is low, but not that low. she didn't confirm it, but we can speculate.
same for Marianne, she willingly lets herself get used and dominated by MC. but she is very thorough, as a character. if she was a virgin, she would have mentioned it to MC because it would affect the quality of her service to him. she is not thousands of years old, the game says she is in her 30s, but it's still enough to at least have some experience and/or some research in sex. it's speculation, but it's based on what is available in the game. again, the dev confirmed her virginity outside of the game, but there is nothing in the game itself.
Titania has children. in a fantasy setting, her race could maybe have kids without sex, but to have kids with MC she immediately jumps on his dick. nothing is explained, so you can speculate that the way she has kids is through sex. she behaves like she is inexperienced with a human dick, though. that would be the only clue that she could be a virgin, but it might just be her first human dick while she had dicks from other races before. until it is explicitly explained in the game that she can have kids without sex, then we can only use the information available in the game which is that she had sex to have the kids she already has, which is also speculation admittedly as those kids might not be hers, and she only refers to them as hers because she is the queen.
if he wants to make their virginity official, why not put it clearly in the game ? it's just a single line of text for each.
LI virginity status is important for a part of the AVN community, so he might have confirmed it because of that, and to make the characters more appealing to fans. I personally don't care, I just want the character history to enjoy the story. MC could be their first, or they could have spent thousands of years getting railed non stop in brothels, I don't care, it's part of their story, I accept it as fact to get a better understanding of the character and how they interact with the others.