It’s been this way for decades. I had logo’d uniform when I was in junior school in the 80s. My brother had the same in the 70s, and it’s existed long before then. If anything schools are somewhat more flexible now than they used to be, my daughter starts school for the first time next week, and her school just needs the right colours, logos are not mandatory. I’ve heard of other schools just wanting the top most layer (jumper, blazer, whatever) having the logo.