I have a free account and had just played around with using Calendly, as well as some other booking software. I have deleted my connection with my Google calendar through my Calendly account, and all of the open slots are still showing on my Google calendar. I have also cancelled any availability through my account so there shouldn’t be anything to show on a calendar.
I might want to use this in the future, but I find it really annoying that it shows all of my open slots from Calendly, basically filling all of my calendar indefinitely. Being a small business that is just starting out, this is something I don’t rely on every day so I don’t want to see it there.