To the best of my knowledge, no - although quite a few people have asked about it. So no gigabit ethernet out-of-the-box.
For those that care about these things, gigabit ethernet is 802.11ab 
Some people have chosen to get a USB 3 to gigabit ethernet dongle e.g. Terrible WiFi performance with Librem13, Librem15 - #101 by vmedea
It is a pity that Purism doesn’t sell a suitable dongle, for those that want ethernet - or just add an ethernet port .