Your VPN provider could have an ingress point on same ISP and as long as egress was not on same ISP you are still fine.it basically reduces to "don't be an idio

Your VPN provider could have an ingress point on same ISP and as long as egress was not on same ISP you are still fine.it basically reduces to "don't be an idiot and choose some cheap/un-audited/amateur VPN provider". If worried then use something like Streisand or other roll-your-own option and use a cloud provider unrelated to ISP.