Though you're right that it doesn't make as much difference now, I'd be wary of assuming that hyperlexia can be safely put in the past once they're old enough that they'd be expected to read anyway.
I was hyperlexic (started identifying brands and symbols at 18m, fluent reader of pretty much anything by 3, at 3½ was discovered at nursery sitting in the big chair in the story corner, reading a story out loud with several other children sat round listening, was never taught but apparently picked it up from being read to) and have talked with other adults who were hyperlexic as children, and although the broader relevance of my and their experiences is somewhat limited by the fact that I was only able to discuss it with people who can and wish to talk online about it, we identified some noticeable similarities in the way we think, and in some of our life experiences, that differed from those with ASD and no hyperlexia.
For example, despite the fact I learnt to speak largely normally, alongside learning to read, I have always experienced my word-thoughts as something more like a ticker-tape of text words than a string of mental speech. This means that when people speak to me and I speak back, I'm often translating back and forth from text to speech and vice versa, which can slow things down and makes the whole thing much harder work than it probably is for someone who thinks in sound-words. I came across several other people who'd been hyperlexic who agreed that their native thought medium was text, too.
There are also difficulties with relevant materials and unreasonable expectations — I was tested at a 14+ reading age (i.e. adult, on that test) at infant school, meaning that age-appropriate and interesting but challenging reading materials could be awkward to find, and that expectations of my abilities were too high in other areas. My urge to constantly read meant that any book I could get my hands on was fair game, and I read quite a lot of books far younger than I really should. Plus I had difficulties with coping with and accepting text with errors, and nobody likes a 5 year old correcting their apostrophes.
Some of this will be less relevant depending on the person's overall profile of difficulties and challenges, but I'd say that being hyperlexic has some (minor) lifelong effects, and isn't only relevant for preschoolers.
@Itisbetter is right in that you can view hyperlexia as an opportunity to connect and possibly to find potential routes in to communication. In my experience hyperlexics are highly, highly motivated to decode text at every opportunity, though I guess other factors affect how much you can make use of that.