Could be. But it would be great if they'd just say having had a confirmed case is equivalent to getting the vaccine because several studies have now shown that to be roughly the case. It's also conventional medical wisdom although it varies by virus.
You'll notice they say - we don't have enough data. Then data is incomplete. Then we can't really say because study was X / Y / Z.
They ignore the MASSIVE difference in your chance of being infected if you are unvaccinated and have not been infected vs many other combos.
Just treat folks who've been infected as vaccinated, they can get booster / variant shots with everyone else when the time comes.
The UK is enterring a third wave, and has a high number of elderly people having been fully (2 shot, mainly AZ) vaccinated. Early indications are that those enterring hospitals now on the whole have not been fully vaccinated.
There are still many over 70s who haven't had any shots though. My (estranged) uncle and his mother-in-law haven't left the house for 18 months, he disinfects his food deliveries and leaves the post in a box for 3 days. He refuses to get the vaccine because he's worried about catching it. Chances are he won't end up in hospital either, but people like that could skew the cases as more data comes out to allow spurious claims from anti-vaxers (They might claim that 'before 2 in every 100 over 80s were going into hospital) , now it's only 1 in every 100 unvaccinated over 80s going in to hospital), because the chance of catching covid from the population still unvaccinated dwindles because of continued isolation
Edit: nicely presented here: https://www.bmj.com/content/370/bmj.m3259
This is a weird trend these days. Medical science refuses to take an engineering approach to anything and only accepts statements based on controlled studies. That includes rejecting previous understanding of how immunity works in general. Early on when claims were made about HCQ, Zinc, or whatever, they were shot down as "not approved treatment" even though there were no approved treatments! The utter failure to recommend vitamin D supplements is another failure - we know deficiency weakens immune response, we know most (Americans) are deficient in the winter, it's a no-brainer but in their mind it was not "proven" so not even mentioned or recommended for anyone.
The only pattern I see considering all cases like that is the underlying notion that people must not do anything for themselves.
The same goes for variants, which a lot of people expect to break through vaccines because that's how the flu works, but it doesn't actually seem like they will.