Not at all, a fascinating subject as far as I am concerned.
I have not been able to find a core formed bowl of any description in the couple of books I have which deal with the history of glassmaking. There are bowls from a roughly similar time period which are slumped or cast so I think either would be more likely than core formed. In this case I think cast looks favourite, perhaps a technique similar to lost wax. I could imagine Daum making something quite like it in the early 20th century....
To own a bit of glass like that in that time period would have been serious bling, very high status.