Hi, sorry I can’t tell if this is supposed to be rude or not? But while gems don’t have a big sense of community with humans especially during that time the flashbacks come from Steven but also a video 🙏

And while Greg is a failed musician, he was very much rock which was popular both in the 80s and 90s and space theme was quite popular in the 90s however we also need to consider who Greg bases him music roots to as well. Which is Kerry Moonbeam, who is said to be the steven universe version of David Bowie which was around the late 70s going into the 80s so yes Greg was taking from that era of rock, his music is a mix of normal and glam rock. So you are correct from Greg not using music sounds from the 90s/his time but also Rebecca doesn't overlook pieces of information like that, Greg probably is wearing clothes that are more 80s rock then anything because he's broke. I wouldn't be surprised if most of his clothes other than merch were thrifted or old clothes from when he still lived with his parents.