Hi, carteratkins!
My name is Caio and I'll be happy to help you today =)
In fact, yes. Code obfuscation is not allowed when publishing apps in MS Store. However, this doesn't means that's the reason why they haven't implemented the system just on the browser version, they might be using another solution.
I hope this helps you! Please let me know if I can assist you more.
Best regards,
Caio G.
Independent Advisor