Here's a link to the reversal of the CA ban.
Glofish are a very tricky topic. Transgenic animals are banned in the EU, but the US FDA has determined that the production of glofish causes no discomfort to the animals, and that their release into the wild in the US poses a very low risk either to wild populations or to other species of fish. The arguments in the UK seem to center around animal rights - the rights of animals to be free from specious human interference. Traditional religious arguments within the judeo-christian-muslim faiths defending human's right to genetically modify animals point to the dominion of man over the animals. Others within those same faiths might argue the opposite based on concepts of intelligent design. Matters become further complicated when you consider that many humans willingly become transgenic by accepting transplants from other animals, such as replacing human knee tisssue with pig tissue. You've definitely stepped into a hornet's nest.
Many object to the creation of artificial or transgenic animals for purposes other than scientific research that clearly benefit humans or animals due the possibility that harm or suffering will be caused to the research subject or the risk that the modified animal will escape into the wild and cause harm to the ecosystem. In the US, we tend to err on the side of allowing new technologies to proceed unless we can identify the risk of harm. It's a judgment call with no clear black or white answer, in my humble opinion.
That being said, if I were managing a pet shop, I would likely choose not to offer hybrids, genetically modified animals, or even tankbusters arguing nothing more than that my focus is on naturally occurring animals that can be kept healthy and comfortable by fishkeepers using generally available equipment and decor.
Tough call. Will be interested to hear where you fall.