I don't think the Chinese manufacturers have ever cared much about the legality in copying others products. Heck probably a lot of American manufacturers would copy others if they could get away with it.
Holding several Patents, Registered Copyrights and Trademarks I can tell you this...
These items are Country by Country registered, and a patent that is registered in one country has no power whatsoever in another country unless it is registered there too.
If you did not file and register your item in the ROC than a US patent has no sway in the ROC and it will become fair game there in no time at all.
Now, although you can't enforce anything against the company in the ROC who is making these, if you do have grounds for a patent case you could go after the company selling them in the country you have a patent in.
So, if it is found these do infringe, BRP could go after the importer and seller if need be. It won't stop the company from making them, but it will stop the sale in the country they bring the case in.
However, patent cases cost hugh money on both sides to get involved in, and can take years, and years to come to a close.
Maybe BRP is thinking these will get people thinking about this "kind of bike" so it's a bit of cross marketing? But, when people see how cheaply these are made than they will "step up" to the real thing and in the end get a Spyder?
MM