Equipment Upgrade Notice from Xfinity

I received a very vague email from Comcast about how the cable network was being upgraded in my area. Because of a certificate expiration issue related to the DOCSIS 3.0 modem I’m currently using, I need to upgrade my equipment. 

The email has a link to modems I can upgrade to - most of these modems I scanned through are DOCSIS 3.1 modems. I’m using a service tier that is on the low end. Do I need to upgrade to a DOCSIS 3.1 modem or are there DOCSIS 3.0 modems that can be used with a low speed service tier after the network is upgraded in my area?