This is an email I received from Dynadot. Posting it here in case people didn't see.
This notice is to inform you of an update to our renewal grace period policy. As you know, with many top-level domains (TLDs), we give you up to a 40 day grace renewal period that allows you to renew your domain at the same price after it has expired. Starting April 15 00:00 UTC, we will be reducing this period by 10 days for each TLD. During the final 10 days of the TLDs renewal grace period, you will still be able to renew your domain, but with an additional late renewal fee of $10.
For example, if you own a .COM domain that expires on January 1, 2018, you would be able to renew your domain at the regular renewal price until January 30, 2018. After this date and until the domain is deleted on February 9, 2018, you would be charged a $10 late renewal fee, so your total renewal cost would be $20.99 ($10 fee + $10.99 regular renewal price).
Please note that we do start sending renewal notices out 60 days in advance of your expiration date. We recommend you keep your account email up-to-date to ensure you receive these messages. We also offer the option to set a different renewal email address and set your domains to auto-renew.
For a little additional information on the $10 late-renewal fee mentioned above, please see this help file: https://www.dynadot.com/community/help/question/late-renewal-fee