I've thought about this before, and I've more or less come up with 3 possibilities if we're assuming that paradise/heaven is real:
1. The realist/tradionalist route: No, there won't be any waifus or husbandos in heaven. They're a concept, a written character, not someone that was alive at any given time, as such, they will not be in paradise. If you do it for one character, then you would need to do it for every written character in existence. Of course if this was paradise, there would be no issue with over crowding, but the larger issue is why give such a privilege to a concept rather than a human? In addition to this, it would be difficult to give life/sentience to someone who's entire personality/story/feelings were never written or revealed. (More of a pessimistic/negative view than the others, but perhaps the most "logical" mindset).
2. The idealist/preferred route: Of course, it is paradise after all, right? If it's supposed to be a place of perfection it would only be right that our spouses were there with us. That's what the rest of eternity would hold for us, living the life we couldn't originally have with our loves. (What most people probably want, although the big issue I see with this is what if two people share the same waifu, or alternatively for normies what if person A loves person B, but person B always loved person C? Who does person B end up with then?)
3. The middle of the road/romantic route: Primarily no, or rather not our exact waifu/husbando would be there waiting for us, but someone extremely similar. This idea relies a bit more on the idea of soul mates, if you're into that sort of thing. Right now there's over 8 billion people on the planet, and several billion have died over the last x amount of years. Chances are (for most people here) at one point or another there existed someone with similar looks/traits to your spouse (albeit in 3D). That person would be waiting for you in paradise or alternatively you'd be waiting for them. In either situation, by some stroke of luck they are more or less your waifu/husbando completely, although perhaps with slight differences such as name. (This one is a bit more for fun, but I always found it an interesting concept, i.e. someone died alone/at a young age hundreds of years ago and has been waiting for their future soul mate ever since).
But yeah, those were the big three possibilities I've thought of. I don't think anyone wants choice 1, choice 2 is probably the best over all but I wouldn't necessarily be opposed to choice 3 either. Picture hopefully unrelated.