There’s a reason why universities (a lot of them) haven’t made a change to requirements for young people with speakers at home. Has no impact on performance, at all
Whether universities regard "home language" qualifications differently depends on what course it is and why they are valuing a foreign language. If the degree (and the kind of career that candidates are expected to go into) is unrelated to the language in any way, most universities do regard "home language" qualifications differently, because their main reason for valuing a MFL is that it is seen as a mark of "academic seriousness" in a candidate, and taking GCSEs and A-Levels in a language at the standards ages even though you had a big head start does not involve as much work or challenge as doing the language "from scratch " would. (Of course, it's different if the language is beneficial for practical purposes---like Arabic if you are going to go into a field of work where that is going to be useful.)
Of course growing up speaking a language at homeor even being passively bilingualgives you a big advantage.
It is of course true that an A-level requires things like studying literature which most "home language speakers" will have to actively study as well--nobody is denying that an A-level will demand work from a "home language" candidate as well. But if you already have a decent grasp of the syntax and grammar and phonetic system (and of course, the ability to "listen" effortlessly), this frees up huge amounts of headspace for studying literature and culture and formal language. Similarly, yes of course "home language" users are often somewhat lacking in the more formal and abstract language. But if you've already acquired a decent vocabulary of a few thousand words, you've then got lots of time and energy available for mastering the more complex vocabulary, while the starting-from-scratch foreign language learners are still slogging away trying to memorize the more basic vocabulary.
We are a bilingual family as are most of our friends here, so I'm very much aware that home language learners have to work hard to improve their language skills (as do their parents). But it's so silly to claim that they are not starting off from a hugely advantageous position.