"For accounts opened after 7/31/19, with By the Gig lines, a minimum $12.00 charge applies per month, regardless of data usage. Data charge applies to each GB or partial GB of shared data. Data shared monthly with other By the Gig lines. No rollover data."
Old
accounts remain under the old rules so you can add new lines etc under the old rules.
There is also a $20 charge per month if you do not maintain another xfinity service (up from $10)
And a couple of new plan tiers:
3gb for $30
10gb for $60
A few other changes so check out the website for full details:
www.xfinity.com/mobile/plan
Unfortunately not as good a deal for new customers but at least old ones get to keep their plans.