Apple replaced its proprietary MagSafe with USB-C for the latest MacBook, so there's precedent.
(Aside: but I wonder if magnetic connectors are even appropriate for a cable that can transmit data as well as power. With MagSafe, if the cable was disconnected, the laptop battery would take over and you'd be fine, but with thew new MacBook you'd potentially have data loss if you had a hard drive daisy-chained in. So perhaps that's a factor in why they got rid of magnetic connectors?)
(Aside: but I wonder if magnetic connectors are even appropriate for a cable that can transmit data as well as power. With MagSafe, if the cable was disconnected, the laptop battery would take over and you'd be fine, but with thew new MacBook you'd potentially have data loss if you had a hard drive daisy-chained in. So perhaps that's a factor in why they got rid of magnetic connectors?)