Apparently the question was reopened because
Nord Stream II is out of question now.
Well, maybe. If Ukraine does something dramatic and blows up the pipelines, NS II could be quickly opened. Its approval process was just suspended, as far as I can tell. The pipeline is fully built.
It's also worth noting that some countries like Hungary already seem to bypass Ukraine more than before by getting more of their Russia gas via the other fairly new pipeline from Turkey (through Bulgaria and Serbia--opened in Jan 2021).
Under the deal, Gazprom would ship 4.5 billion cubic meters of natural gas to Hungary annually, allowing the supply of around half of Hungary's annual gas consumption.
Two routes will be used -- 3.5 billion cubic meters will come via Serbia and 1 billion cubic meters via Austria.
Some of these Eastern EU countries like Hungary and Bulgaria did give their half-hearted approval to the EU to send weapons to Ukraine, but they completely ruled out sending any weapons themselves. Hungary even blocks any weapons for Ukraine from even transiting Hungarian territory. If Ukraine does something to annoy these countries even more, Hungary could e.g. start blocking EU decisions on helping Ukraine, which by the way, they used to do with regard to Ukraine's NATO membership.
And probably even Poland, Slovakia, and Romania, which are sending weapons (or at least ammo in Romania's case) to Ukraine, would object to suffering a sudden energy crisis since they still get a sizeable fraction of their natural gas from Russia, via Ukraine.
By the way, according to one analyst, NS2 was supposed to be the "final nail in the coffin" of gas transit through Ukraine, given the other pipelines that Russia has built in the meantime:
the role of Ukraine is smaller today than it was in the late ’90s. There was a time when 90 percent of the gas that comes from Russia to Europe went through Ukraine. Now it’s less than a quarter. So all the stuff people say, like “Nord Stream 2 is going to kill Ukraine and [gas] transit,” like, yes, Nord Stream 2 is the final nail in the coffin of a Ukrainian transit story that has been in demise for 25 years.
According to the same source, cutting EU's gas imports from Russia would hurt the EU more than Russia, because the latter makes relatively little profit from natural gas relative to oil sales. (Although no figures are provided.) Somewhat simplified pipeline supply explanation map, from the Economist:
The EU itself is trying wean off the Russian gas, but...
One of the biggest hurdles to replacing so much gas this year is securing enough LNG.
The [EU] Commission says around 10 bcm of gas imports could come from alternative pipeline suppliers, while 50 bcm would be LNG. That is equivalent to around 10% of annual global LNG supply.
"Obtaining this volume will be difficult: 50 bcm would represent a major additional draw on an already-tight global LNG market and additional demand cannot be met by significant new capacity before the mid-2020s," Jesse Scott at German-based thinktank Agora Energiewende said. [...]
U.S. exporters have shipped record volumes of LNG to Europe for three consecutive months, at prices at least 10 times higher than a year ago.
The cost (for the EU) of entirely replacing the Russian supplies has been estimated at around one hunderd billion euros per year, given current prices.
