Is this a new one? Is there any link you could provide for us to check? There have been many platforms that bridges Ethereum and layer 2 networks or other chains but they are still not spared from the fees on their first transfer.
...If this happens would it matter for ETH Devs to still do anything about the high gas fee?
Yes it does since many people still prefer transferring funds without using third party apps or platforms.
Plus the Devs understands that they will want the users back so I don't think because there is a system where people can bridge from Ethe Network to other Networks will make the Eth Devs give up on finding a solution to the gas issues except they feel those people are no longer needed which I doubt.