Indeed. Although technically it's UCS-2 as the low level stuff doesn't understand modern unicode; it just treats it all as a stream of wide chars. It's up to applications to interpret it.
According to this[0] the path limit is nearer 32739*2 bytes as a drive like "C:" gets expanded to "\Device\HarddiskVolume1".
Except if it's a compound emoji, which takes multiple codepoints -> more than 4 bytes.
So really the takeaway is that "character" is highly ambiguous nowadays and shouldn't be used anymore, use one of these instead:
* UTF-n code unit
* Unicode code point
* Grapheme Cluster
* Extended Grapheme Cluster
For the latter one also needs to specify the version of Unicode they're talking about, since every new compound emojis changes the definition of "Extended Grapheme Cluster".