Airbus certainly won't be giving away the mod kits for free, there will have been a bean-counter involved at some stage.
"Vortex generators will be installed on 130 existing JetBlue A320 aircraft and eight JetBlue A321 aircraft during their existing scheduled heavy checks with the full fleet wide install expected to be complete in 2021. All future Airbus orders will be delivered with vortex generators already installed. The cost to retrofit the full Airbus fleet is less than $1 million."
https://www.businesswire.com/news/ho...tex-Generators