Well if you look at WW2 not as World War 2 but as a war where the industrialization and automation of industry revolutionized the way to act out war then yes it would still eventually happen and in such a chain of converters HOI4 would still be quite important.
Can't forget the ideologies. Defeated parties from WW1, that didn't have Commu/Socialist revolutions would almost certainly swing fascist. The three sets of blocs would form relatively naturally. Hell, Victoria's crisis system alone tends to create longstanding political alliances. You port that into a WW1 scenario (either end of Victoria or a stand-alone WW1 module for HoI4) and you'll be able to set things up rather easily.