In Mogens Schluter's brief history of Kastrup-Holmegaard he [...] doesn't go into what caused Danish glass, after 100 years, to suddenly move into modern art glass, unfortunately.
Just finished translating a chapter in another Mogens Schluter book on Holmegaard, and apparently they first moved into art glass because the Royal Copenhagen porcelain factory requested that the glassworks create drinkware that matched their dinnerware sets, so in 1923 Holmegaard and Royal Copenhagen signed a contract that ensured future collaboration.
Holmegaard hired an artist called Oluf Jensen to create the first designer-lead glass for the factory, the first of which was called 'Lace', a set of drinking engraved drinking glasses with a design that matched a Royal Copenhagen series of the same name.
Jensen only submitted a few designs before quitting, and was replaced by a young artist of the name Orla Juul Nielsen. Nielsen had recently won a design competition for a drinksware set, which is what brought him to the attention of the glassworks. Nielsen was a prolific designer for the few years he was at Holmegaard, representing them at the 1925 Paris World Exhibition with the 'Tranquebar' range.
Collaboration with Royal Copenhagen only lasted a few years, and Nielsen left in 1929.
The book then goes on to say how JE Bang saved Holmegaard with innovative new designs, etc... with no further mention of Nielsen, as far as I can see.