>>82353688Gura definitely brought in a large number of English-speaking viewers, but Hololive would have thrived either way after China unleashed their virus on everyone. There were already about 10 of them in the 500-900k range prior to Myth's debut, and the top ones like Fubuki and Korone were growing at a rate of about 100k subs a month at the time.
Nowadays she could be considered the the most recognisable EN vtuber, but if she graduated for innocuous reasons, while it would have some impact, in all likelihood it would actually be negligible in the long run.
I just don't think there's much of an overlap in the venn diagram of "people who are interested in hololive" and "people who would not be interested in hololive without Gura". They'd find a new face or new faces for EN and continue business as usual.