Not sure where you got your info from.
https://www.sixthtone.com/news/1005609/after-multiple-deaths%2C-officials-call-for-no-masks-in-gym-class
This was early-May, with a bunch of cases since then with similar outcomes, including a few people in the US who died in car accidents wearing N95 respirators while driving.
They never proved that it was absolutely not from the masks, the causes are still unknown in all cases except one I saw that was a heart attack, likely unrelated to mask. There's a big difference between definitely not and not definitely.
My point being that there is also some potential risk in high intensity activity in a mask.
I just do not buy that a splash guard is going to dramatically reduce the risk if playing indoor ice hockey. I think it's actually wrong to perpetuate that information, since the reality is that many people will buy them and just figure that they're protected and good to go. I think that the risk of playing with the splash guard is similar to the risk if playing without it, and I think that without the splash guard people are likely to be more cautious of contact than with it. I actually think that this is just a way for people to convince themselves that there is less risk involved in playing than there really is, and that actually hurts the effort to halt the spread of the virus.
Bottom line, there is risk involved in playing and I don't think the splash guard is going to mitigate that risk (and it had NOT been proven to), but I think it will convince enough people that they have mitigated that risk for them to not pay proper attention to avoiding contact during play and on benches. Thus, I feel it is actually doing more damage than good.
I think the best approach is to just be very clear about the whole situation. There is significant risk of infection playing indoor ice hockey. There is very little that will change this while still allowing play to be enjoyable and functional (IMO). For most young people, the virus is not dangerous, but the risk is that, while they will probably be fine, by playing, they risk picking up the virus and spreading it to someone who won't be fine. With that being the case, people should decide what they want to do and what risk they are willing to take. They can also decide to wear the splash guard or a mask if they believe it may help. They should know that there may be some risk in that as well.
I think this is pretty simple and sensible, and I think it will help people make better decisions, rather than relying on all of these products that are completely unproven and then mandating them for play and then completely not enforcing any of it, which is what's actually happening.