In this case the VPN "provider" is the router itself and since you owned it you can eliminate logs. The ISP may have flow-level logs but those are so voluminous that they probably aren't kept long.
The parent comment was(pretty clearly) referring to what you're calling "flow-level logs"... Quite obviously you can delete the router's logs(it's mentioned in the article and by the parent comment); the ISP's traffic logs on the other hand?
> those are so voluminous that they probably aren't kept long.
