Font Missing Articulate 360
in the case a SL1 file to be updated in SL2 and missing a font, in my opinion there is no interaction to block the import in SL 360.
By clicking on "Learn more about font", there is written in the matched page
"This gives you the opportunity to install the missing fonts on your computer or replace them with another font in Storyline."
But there is really no way to install missing fonts!