Putin is trying to intimidate Sweden and Finland, by threatening to move military units and weapons around if they join NATO.

Putin is talking about their membership in NATO as if it constituted a threat to attack Russia (which is not true). I think the purpose of that way of speaking is to encourage people to conceive of it that way.

Russia can move its troops and missiles around for any reason, or no reason. Putin could have moved troops to the Finnish border a year ago if it wanted to, but there was no reason to do so then, and will be no reason to do so next year, except to look bellicose. It wouldn't make any big difference in practice anyway.

This is just posturing, but it gives people something to panic about if they are so inclined.