Yes, usually I do not even prefer accessing any crypto related services through google account; I always prefer registering a new account using email or username. I will never prefer giving access to telegram (or any third party) to my exchanges and let them see my balances nor my trading activities.
This also concerns me in using such services, especially on Telegram. I don't know if it works that way or not. Still, it seems that they can see and monitor every activity we do with our Telegram account, including what apps we use, what activities we do, or maybe even access those apps since they have complete control over our accounts because it's a centralized messaging app.
This is why, even though I agree that it helps increase adoption for cryptocurrencies in general because Telegram mini apps and games are currently treding and almost one out of every ten people would be a part of them, using financial apps on the platform seems like giving control over your finances to another third-party on top of using a centralized exchange which is already a centralized service in itself.