No it wouldn’t. Vanilla to MoP had separate currencies that can allow you to not only buy gear but mounts as well. I think this game will be fine with more currencies, considering Shadowlands has more systems in it then Legion at this point.
The only place you can get the store mounts are from the store. There are not regular drops like other mounts or vendors and such things like that in the actual ingame. In terms of immersion, you practically get those mounts out of nowhere with a possibility of your gold pouch being smaller somehow.
What’s so confusing about trying to understand my and Yranda’s points?
I’m sorry, but have you never played WoW before? WoW has those things since it’s inception and always still gonna have them. 
Alright, here’s a couple of topics i’ve found that goes in depth of what i’m talking about.
https://us.forums.blizzard.com/en/wow/t/why-does-community-defend-pay-to-win-aspects/162505
https://us.forums.blizzard.com/en/wow/t/wow-pay-to-win-situation/525056
The Taxed Largely; Didn’t Rent version is, Patch 8.3 dropped in that time and that came with it is corruptions. Since corruptions can be on anything, and very powerful, it can be on BoEs and people can sell BoEs to make money. Because WoW Tokens are part of WoW, meaning you can buy gold, the people who sold the BoEs are selling it for very high amounts because the corruptions are very powerful. Because of that, it’s why people were calling it Pay to Win. Even Asmongold has called it that.
While we can blame the people selling the gear here, let’s not forget that it was Blizzard who put it in and allowed it to be on anything. Mind you, Blizzard didn’t really attempt to stop this until Shadowlands pre-patch.