We made a similar transition from Scrum to a mix of Scrum and Kanban (Scrumban).
We kept the biweekly demos, because the intent was to continue to provide regular transparency. We did not keep the biweekly “sprint commitment” which — much like your story — forced (a) significant overhead around trying to estimate accurately, (b) corner cutting to get stories finished by that artificial cutoff, and (c) no improvement in the ability to project more accurately in the macro perspective.
Another factor was scheduling — some rituals like sprint kickoff and story elaboration were forced into a given time/day of the week, which interfered with the shared product manager/product owner’s ability to do the “product management” side of that job.
Great to read an example of someone making a similar transition and seeing equally positive results.
You can read more about our experience in the original post on my blog.