Sort of, but it is also sales-blather.
No RV can be officially designated for use as a fulltime residence because that violates the residential building codes in all 50 states. That's a legal technicality, but it leads to disclaimers about "use as a residence" in most RV makers literature.
This is a typical disclaimer, taken from a Jayco owner manual:
This recreation vehicle is not intended for use as a full-time residence or for commercial use.
However, the distinction between use as a "fulltime residence" and "fulltime recreation" use is a decidedly gray area. If you park it in an RV park it is considered an RV in most communities, even if you stay there indefinitely, but if you park the same RV on a residential lot and sleep in it one night, most communities consider that it has become a residence (and an illegal one).
OK, putting that legality aside and focusing on valid recreational use, yes some manufacturers may state that the vehicle is intended for seasonal or part time use only, meaning that fulltime use constitutes "abuse" for warranty purposes. I've seen that wording here and there, though I don't recall brands or models. Since those RVs are mostly warranted for only 12 months anyway, I'm not sure it is a practical distinction.
My personal opinion is that intended fulltime use dictates getting a rig that is built using better grade materials and a higher standard of workmanship. I'm talking about cabinet work, flooring & upholstery as well as a sturdy frame underneath and well-built roof & sidewalls, plumbing and electrical work that is protected from vibration, well labeled, and accessible for repair, and numerous other details. That generally means a more expensive unit.