That is exactly the reason why Ukraine would blow up Nordstream - and why it makes absolutely no reason for Russia to do so. Russia could use Nordstream to sell gas to Europe while bypassing Ukraine. That was literally what it was built for, as Ukraine has, a few times, been late on their payments for the gas, and Russia couldn't turn it off without interrupting supply to their paying customers. So Russia had absolutely zero reason to blow up Nordstream, except maybe as a weird, self-defeating false flag operation.. If anything, the US would have a lot more motivation to do so, as now they can shill their LNG to Europe (specifically to Germany who has stupidly disassembled their nuclear power plants and is relying on gas and coal for energy production).
So with all the crap that Russians have done lately, in my book, the Nordstream blowout will always be a US commercial interests project.