Does my Pixel Fold need to be OEM Unlocked to install /e/OS?
I’m currently on T-Mobile and I have a couple months of paying off the device in whole.
I’m not sure if my device will be able to be OEM Unlocked from T-Mobile
Regain your privacy! Adopt /e/OS the deGoogled mobile OS and online services
First check the install page Install /e/OS on a Google Pixel Fold - “felix”. Yes, OEM unlock is required.
Best to ask T-mobile. Typically is USA many phones are well locked down.
Either locked SIM or locked bootloader they will know if they are prepared to serve you after installing a Custom ROM.
Well if I pay off my device it’s fully mine 
Ever the optimist, I see. My experience suggests that it will be fully yours but with whatever T&C were set up on purchase.
Perhaps a USA T-mobile user will chip in with more factual answer to the bootloader unlock issue. You are likely to have to speak to them as the phone will at a minimum appear to them changed by /e/OS install.
I’m no authority, but I’m pretty sure all devices must be OEM unlocked, i.e. the bootloader must be unlocked (←I’ve edited the preceding italicised phrase to fix an incorrect portion), before a custom ROM can be installed.
Implied in your question, I think, is whether your T-mobile branded device must be carrier unlocked before the OEM unlock (←edited). I don’t know the answer to that. Have you checked in the device’s service menu to see if unlocking is possible?
I have this issue here, I opened something on gitlab but no response yet.:
When I first started the thread, my internet searches indicate that some US carriers disable (in my case WiFi calling) when the bootloader is unlocked. The Canadian version or the ROM does not do this. I ran the stock ROM with the bootloader unlocked and WiFi calling works (again Canadian ROM).
I think the eOS build of the device is based on a US ROM and one of the company’s that disable WiFi calling. I think if this device was built (and maybe others) with the Canadian ROM the WiFi calling would work. Just my thoughts on that.
The good news is I have never seen a Google phone and I have done the 4a5G, 5, 6, 6a and 7 that the WiFi calling did not work. So if history repeats itself all features will probably work in this phone. It may be that the google phones get the features from a different place in the ROM than the Moto phones do.