I cannot fathom what 2k+ trainer is "training" you by using you as deadweight to farm rating by pushing themselves and you up 1900 points by crushing 1100 rated players. Sounds like you were getting asked to do some rating pump and dump scheme, let me know the trainer that told you that so I can get a talk going about it in the trainer channel. They are actively ruining the game for you by giving you a fake rating that will then proceed to get you totally throttled.
The advice 2k+ trainers won't relate to "the current state of the meta" because effectively everyone (that I have ever talked to, maybe Russian trainers are different) tells sub 1k players to focus on the fundamentals I mentioned above. Meta matters when you care about what is efficient mass-for-mass but the reality of the game is that you can brute force anything as a win condition when you have triple the mass in it. And the reality of sub 1k gameplay is that you can have triple the mass generation if you are playing at a 2k+ level.
Obviously nobody EXPECTS you to macro like a 2k rated player, but it's the ultimate way to improve. There is no point focusing on marginal points like meta or specific unit mixes or what units are good and when they're good if you can't fathom why you NEED units first. Likewise, it matters 0 to you if UEF destro sucks compared to Aeon destro because if you have 1.5x the mass in it, you win anyway. You understand why stuff is important by understanding the flow chart of scaling. You need to understand what a t2 mex is, how much it costs, how it compares to losing some map control, and how powerful some tanks are. There are the fundamental blocks that make you derive the first tradeoff of eco vs units. Before that, you have simply grabbing your map half as fast as possible, which also involves units because going pure engies (pure greed) is punished by a balanced playstyle of many tanks and a few engies (pure aggressive) which is punished by a few tanks and more engies (more passive) which is punished by pure engies (pure greed). How do you know what to do? Gotta learn how to read the map (terrain, mexes, reclaim) and how to scout and read opponent. These are skills built by doing what you described, playing the game. The more you play the more improvement you will see. If you just play 2 games a week, don't expect much progress. Same as any hobby.
I KINDA feel like you weren't actually referred or talking to trainers, and for that I can't really give you a solution. Trainers are given a special color for their nickname because you should prioritize their advice for this stuff. If you listen to random dudes, even if they are 2k, well some are just useless or dickheads or both. Can't really stop the free market of ideas from them and start banning everyone with bad advice because then you also end up banning the dudes trying to learn by giving each other public advice and then getting feedback on said advice.
And no, this macro stuff isn't up to meta. It's sheer mathematical reality what is the optimal scaling path. If you can't recognize the properties, it's just flat out not possible for you to make coherent decisions regarding when to make units nor will it matter what unit is better. When you get into those aspects, that becomes the subjective meta, but that isn't the focus until you are at least 1000.