Not sure if you are aware that 2 years ago, TI ended distribution through all but a tiny handful of distributors (Digi-Key and Mouser being the main two). Everyone else got dropped.
Ah, I didn't know that. Even so, I'd've thought they would be keen to have their data spread far and wide - in the end it is advertising, and we all know how difficult it is to block that!
Well, I doubt it was at TI's request: a few TI products on RS
do have TI datasheets and manuals (all dev boards, though, which may not fall under the distributor cull). So I suspect it's RS's decision, and that the rep who replied to you simply gave a boilerplate response without doing any investigation whatsoever.
I checked a few other former/unofficial distributors, and one (Distrelec) seems to have no TI datasheets, which I am fairly sure they used to. But two others (Reichelt and Jameco) have datasheets, so it's unclear whether TI is asking RS and others to take down datasheets.
If I had to guess, I'd speculate that the former distributors signed something way back when, saying that as distributors, they're entitled to share TI documentation. And once their distribution contract was terminated, the distributors' lawyers said to take down the docs to be on the safe side. But this is pure speculation, I have no evidence either way.