The RTC well (powers the CMOS RAM and clock) is also powered by the system battery, which means the CMOS battery is mainly for redundancy if the system battery is so discharged that it can’t power the RTC well.
We did start adding them though as loss of the RTC clock is more impactful to systems using PureBoot with a Librem Key than to the average computer that can just sync it again after boot. (The RTC clock relates to GPG key validity and TOTP if you use it as a backup for HOTP, all of which happens when there is no network connectivity.)
edit: And there’s no Librem 14 v2 yet, the minor revision made recently is called v1-02. Some components changed like the audio codec and CPU stepping, but there’s not really any functional difference so it’s still v1.