T80BVM and T72B3 are both from 2013 , T90MS is 2018. This is literally their latest kit. According to some source T-14 production has stopped and T90 production has slowed, resulting in the modernisation programme of T72`s and reactivation of T64`s.
To expand slightly on this, when it comes to Russia there is quite a distinction between "latest kit" and actually modern/decent kit, I.E:
The T-72B3 Russia launched in 2013 are not new tanks, it is an upgrade package for older T-72B tanks, and it's not even a high end package it's a budget package so that 30+ year old tanks can be upgraded cheaply without having to buy the superior T-72B2 package. Estimates were they only had around 600 of these when the war started.
The T-80BVM is again an upgrade package for existing tanks (and this time they had 200-250 when the war started), but having to send any of these highlights the severe issues Russia is having because the Russian variants of the T-80 are not offensive tanks. They are cold weather tanks designed for defence whose MPG make them completely unsuitable for any kind of invasion. The fact Russia are sending gas turbine T-80s into Ukraine instead of using them to replace T-72/90 in service in Russia and sending them instead, shows how dire the tank situation has truly become for Russia. (NB: There is/was a diesel variant of the T-80 designed/produced for regular operation but Russia retired all of theirs in the 90s along with their T-64s as both tanks were designed/produced in Ukraine and they couldn't afford to import the parts to maintain them).
The T-90MS is a four year old update to the T-90M, which was an upgraded T-90A, which was an upgraded T-90, which was an upgraded T-72B. The idea that a recent T-90 is in any way noticeably better than a recent T-72 is simply marketing propaganda designed to make middle eastern dictators pay more for them.
This is Russia's main tank problem, aside from two T-14 prototypes they haven't actually built a tank since 1972, they've just been slapping upgrades onto their T-72 and Ukraine's T-64/T-80 and pretending like they make tanks. The reason so many people think they are "holding back" their "good kit" is simply because they have so little of it to send it looks like it's not being sent.