Did you read? These are not Tesla workers blocking a port from unloading Tesla cars.

No, they are port workers doing a sympathy strike with IF Metall, they are workers that see collective action taken against Tesla and decided to join in on their field.

Tesla workers under IF Metall are under strike, there are scabs in any strike, Tesla was ferrying workers from other places to cross picket lines and do the work, that doesn't fly here in Sweden, hence the sympathy strikes by other unions to show Tesla that this attitude is despicable in this society.