I saw this as well when I first got the gateway and decided to block it. Started having issues with slower connections. Today, I re-enabled it after doing some research. I wouldn't depend on TMOBILE employees ever giving a straight answer to any questions. Their answers are often from employee manuals. If not found, then they're lost for answers. Techs as well.

Farmer151 wrote:

Additional - I do see RDK-B stands for "Reference Design Kit - Broadband". So I agree it is from TMobile or one of their associates to use to launch services - broadband, broadcast, hybrid cpe hardware.  

I’m guessing the GW is short for Gateway. And of course neither of the TMOBILE employees would know a thing about it if they wasn't the ones who write up the software. Meaning the software is part of the ROM system and is needed. I could be wrong. Who knows.