Weird gamertags on xbox live

No they are not developers(devs).

I think the most plausible answer is that they are actual test accounts... or some sort of bot generated account. The biggest red flag is that they start with numbers, which isn't typical of gamertags on Xbox Live. The closest thing to it I could find
past using the 'find someone' button in the friends tab on console, where gamertags that started with special characters. The latest gamertag update made special characters and certain characters from different languages usable in gamertags but starting with
numbers is still rather unusual. The fact its '2' then 'dev' and a rand strain of numbers is probably just the dead give away as to what those accounts are. They all have zero Gamerscore, 0 or no followers, and the number chain is apparently random. I looked
through a good lot of the ones that came up and honestly, there's no reason someone would purposely make that their gamertag.

i think they are bot, like all the gmrgrl1894896515641984 that exists xD

Many times throughout the world, with the infinite possibilities available with gamertags, many people choose the same one. The only way to denote the difference, Xbox automatically puts a nomenclature on the end of it. Basically the same way as a license
plate for a car would change slightly from one to another but still be in the same category.

Hello Psyko wezzal,

Thank you for posting on the Xbox forums. We will be locking this thread due to it being revived by a new post. If there are any questions, discussions or issues that anyone would like to bring to our attention, please create a new thread. We
will be more than happy to answer any questions or provide solutions for any issues. Thank you again and happy gaming Psyko wezzal!