Just to be absolutely 100% sure, and to stop this question for popping up again (I know, it will eventually...

)
I've contacted Frontier Support on the issue of non available pre-orders, and got the following reply:
Hello CMDR.
Thanks for getting in touch.
Unfortunately, some EU regions weren't added for pre-order on the store. This is totally not intentional and we've submitted requests for them now.
I regret that I can't give an ETA at this time but we're hoping to have this resolved just as soon as possible.
Sincere apologies for the inconvenience.
Please don't hesitate to get back in touch at any time if you've any other queries or issues.
So, no worries, it will be there eventually... We just need to be patient, I know it's hard!
PS: With the PlayStation store updating every tuesday, that should be our next target
