This is planned in the near future, but not implemented yet.
If you really need Wireguard immediately, you can use the beta 3.0 firmware on GL.inet routers
I think they submitted the code (revised) again and should get into 5.x kernel. Or at least many of us hope so. If yes, it will be in LE too?
Btw, why is it not possible to add it to kernel on building? Lot of distroes already added, like Armbian.
WG so good, so simple to configure, and resource friendly, something really important on SoC devices on which LE/CE runs most of the time. I couldn't believe how fast speed I am getting from a NanoPi NEO2 with Armbian, compared to OpenVPN.