Adrien Lacombe on Nostr: I'll try :) because it is a soft fork, a tx with OP_CAT will be valid even from nodes ...

I'll try :) because it is a soft fork, a tx with OP_CAT will be valid even from nodes that have not the soft fork. However, because they don't have the soft fork, they can't interpret any script containing OP_CAT and therefore, the inner workings of Bitcoin makes it so that these nodes will see this tx as an anyone can spend. This means that these nodes without the soft fork will interpret as valid any tx spending the utxos locked by the original tx , whereas nodes with the soft fork, will only let a valid tx with the interpretation of the CAT script, spend the utxo. So now let's say the majority of the nodes haven't upgraded, if a CAT tx gets mined somehow, the network would fork as soon as a "stealing" tx would appear because the nodes with the upgrade would reject it. I hope it helps.