No way is UEFA going to move the CL final from St. Petersburg; Gazprom is a major sponsor, if not THE major sponsor. Gazprom is run and owned by the same ex-KGB thugs who are now led by Putin and his cronies. Gazprom has it's roots in St. Petersburg, Putin and his cronies also have their roots there, it is where they learnt to launder money from illegal oil trading, then fraudulently gain control of Russia's banking system and natural resource industries.
We should know by now that UEFA belongs to the same club as the all the other hapless corrupt international organisations, where ethics, fair play and decency are inconvenient obstacles to be navigated around.