[Spencer]

Obviously if the Galaxy brand was ever revived, it would target an older audience who were listening to Galaxy during it's prime in the 2000s, who are now in their 30s & 40s. It could launch as a rival to Kisstory, but as has been noted, launching Galaxy as a standalone brand wouldn't fit in with Global's strategy of their radio business revolving around their already established core brands. 
But a proper digital rival to Kisstory is about the only station that Global does not have. I wouldn't count Heart Dance as a rival to Kisstory, and Capital Dance focusses almost exclusively on newer dance music with just the odd 'throwback'.

Is Capital Xtra Reloaded not their equivalent to Kisstory?