Firstly I dont read this as implied that you were doing something illegal.

Secondly relying on a manufacturer to know/do something illegal isn't the most reliable recomendation where there is a few dollars involved.

Thirdly, with the cancer risks of Tritium, there would plobably be restrictions in place. But newer manufacturing seals it in the glass, then has a second layer of protection.

So newer manufacturing processes would probably be designed to fit in with any restrictions. The concerns raised, I think are relating to older manufacturing. But it wouldnt hurt to check if you are worried.
I would be happy to buy them.