They have not said so, but marlins have dried up and are not available from distributors so the safe bet is that production has stopped.
The only official info that has been put out is the press release saying ruger bought marlin - all rights to the name/products and the entire production line.
Then Ruger put out a press release saying they bought it all and were in the process of moving it to one of their facilities.
That is the extent of the public knowledge as far as I know. Unless somebody has inside knowledge at ruger anything else is speculation.
The moving of such a production line is a large and expensive undertaking. Add in the logistics of setting up outside vendors for parts and materials, hiring people, etc. and it quickly becomes a very large project. I'm not smart, but I've seen much smaller projects take well over a year.
Ruger likes to make money so it's a safe bet the first marlins they make will be those that have the quickest return to profitability.
ETA: checked marlins website, ruger has it and put this up:
https://www.marlinfirearms.com/resources/customer-serviceTLDR: ruger says "anticipate second half of 2021"