This thread is really bizarre actually.
Sizing is literally just a number, it's completely arbitrary. Presumably Primark has done this so they can stock more large sizes without having to go xxxxl xxxxxl etc. They haven't stopped selling lower sizes they've just shifted it one place so it has an extra x at the lower end. That's literally it, I don't understand why you are getting so wound up op? That extra x doesn't make you any smaller it's just a label on clothes.
Primark is just a business, they will make clothes in sizes that sell. The population is getting larger, and Primark wants to sell their products to them. No one has the right to buy clothes from Primark tbh, they are not a government run initiative they are a shop.
Mn is really excessive about vanity sizing, It doesn't matter if your size 8 jeans were really a size 40 in 1901, the 8 is meaningless, it's just a random number really and you're shopping in 2018 so just buy the buy jeans that bloody fit you ffs! Products change with time, nothing ever stays the same, it's capitalism, of course sizes are going to change with time, just as pretty much every other thing we buy does. It just highlights the importance of trying clothes on.
I have said it before but vanity sizing isn't that clothes are getting much bigger it's that they are getting much straighter, waist sizes are increasing whilst hip and bust measurements are staying fairly similar, clothes are changing shape to reflect changes in our population.
Sometimes people will be different sizes because we aren't all the same ratios, for example I am pear shaped so if something is designed to be tight on the waist I will be a much smaller size than if it is designed to sit on the hips.
I also think you will be fine for a while op, my housemate is very small (underweight and 5' ) and still manages to find clothes that fit without too much bother. Remember clothes manufacturers still mostly model their clothes on v. Slim women and most of them design their clothes for slim women. Shops like Primark market an awful lot to teenagers and won't want to stop selling the smaller sizes because that's a huge proportion of their profit gone.
Tbh this rant of the ops was pretty meaningless because there has been no suggestion that they will stop making smaller sizes, only adding an extra x at the small end, and therefore seems to be mostly about pointing out how small op is and how terrible fat people are.