You’ve seen M.2 cards in modern laptops already. If you’re buying an SSD today, it’s most likely an M.2 one. Many of our laptops contain M.2 WiFi cards, the consumer-oriented WWAN cards now ...

Generally, the upgrade is only impossible on such a machine when: its current Wi-Fi card is soldered to the motherboard and can't be replaced -- the rare cases of certain ultra-compact laptops.