Hi Macarena - this is something we're investigating as we speak. Specifically, identifying what we can/cannot do after May 25 with regards to our third-party agencies and channels (like LinkedIn). LinkedIn would be the "data processor" in this case (and your company would continue to be the "data controller"). I think it will take more investigative work to determine what sort of changes LinkedIn will require its members to consent to as part of the end-user agreement. This might already be in place. For example, someone who may have opted-out/unsubscribed from your marketing emails in Marketo have no impact on your ability to target those same users on other channels like social media.
This is one reason why are re-shifting our marketing investments to very targeted, account-centric advertising (paid, social, display, etc.). We currently use a service called Bombora that provides us with valuable "intent" insight on companies who are sending signals (using public data - like social posts, search, websites visited, etc.) that they may be candidates for our offerings.