T-Mobile does not log text messages content unless requested by law enforcement through a warrant.

the numbers that were contacted to and from sure..the actual content of the texts no..the only way that info can be pulled is with a warrant.

Is it still correct that the only way to get text message contents (even though I’m the sender/author) is via a court order/warrant?

Yes.  T-Mobile does not store the contents of text messages  unless directed by a warrant or court order.  

Actually, on your TMobile account you can view text messages. I have a TMobile account and have had to retrieve contacts not saved and was only able to do so by reading our messages, lol.  So, I'm not sure if it's related to the type of plan you have but under text messages, there's a pretty thorough record that you can access.. for calls as well.  Hope this helps! And anyone can subpoena records for themselves, and reference yourself as Pre Se (simply your own attorney) fyi.  Have a blessed day!

I don't think this is true, I went to my Tmobile app and MyTmobile.com and wasn't able to see any content.

Also it's Pro Se not pre se plus what magical plan that you're on that you can see text content on line.