I don't watch those sorts of streams, but they do it during streaming? They change the country-IP in their VPN app and continue playing?

That's laughable because that could become an issue between the provider and the casino itself in the future. Can you post a link of one of those videos?
This action is actually common thing to happen, even some reputable casinos allow this action (changing IP in order to access specific game/provider due to restriction by the provider).
I have done it myself in few different casinos especially when there was contest/competition but I could not play the game due to the provider's restriction, asked the support of the casino and they told me that I can use VPN.
I think Shuffle also take it as not a serious issue, just for example for their previous "hit the target multiplier" weekly promo, there are 5 games from few different providers.
When I tried it, I cant play the first 4 games but the 5th game is not available to be played from my region so lets say I have completed the first 4 multiplier, means that I have to change my IP in order to complete the 5th game.
Of course I'm not advising/recommending others to do it, better to ask support when it comes to this situation but I myself sure that changing IP to bypass provider's restriction is a common thing and some casinos do not take it as something against the terms.
OK, if you go into some sort of problem, kindly post about it for the sake of information-sharing and how to interact/deal with customer support and the casino admins to fix the problem.
Plus it's probably a skill issue. When interacting with customer support we should probably ask the right questions to get the maximum information we could find about the issue. For those people who were asked to list their other accounts, the user should ask the admins what made them believe that the user has more than one account.