Oh Boy did you miss some stuff lmao XD 

The SDCC panel happened on Friday and they screened S7E1 and revealed several new things about Shiro:

Shiro has/had a chronic illness that affected his muscles. He wore some kind of electro-stimulation wristband on his right arm to keep his muscles loose and only had a few years left in peak condition before his health would decline irreparably. The showrunners have said in interviews that when the Galra cloned him they eliminated the sickness from the bodies they created (can’t have a weapon in less than top condition after all) so the new body Shiro’s in now is no longer afflicted

Shiro is queer/mlm! He had a long term boyfriend while he was at the Garrison named Adam. Unfortunately they broke up over disagreements on whether Shiro should participate in the Kerberos mission given his condition (see point above). When asked specifically how Shiro ID’s his sexuality the showrunners deliberately left if open-ended (tho for full disclosure Lauren does refer to him as a gay man in a different interview X) so beyond him being mlm his identity is open to interpretation and all headcanons are valid!

Here are a couple summary posts I’ve found:

Q & A

It’s confirmed that Shiro had a boyfriend on earth before Kerberos named Adam!! They were shown during the first episode that was aired at the SDCC panel earlier today. And then it was explicitly stated that yes they were together, had been for quite a while, but broke up over Shiro wanting to do the Kerberos mission and Adam not wanting him to.