They are advertising as "PRIORITY will improve experience (i.e., latency, etc.) but won't always improve your speeds." They have also mentioned non-priority users won't experience any speed impact.
Advertising-wise, they are playing it safe, and this technically does NOT go against net neutrality as you are not using QoS.
However, I think TRAI might have something to say for it (Jio would want TRAI to do something about it.)
If TRAI does not do anything about it, I am sure Jio will follow suit with something similar, or they'll advertise as, "Unlike Airtel, we give you the best performance at all times, no discrimination."
As a user, I am against BW throttle plans. However, having better net experience for higher plan users is welcome.