The change they made to the scale had to do with advisories using mph and the issues that can cause in the category 4 range. They made the tiny adjustments to impact that. The changes did not impact historical storms.
"It's important to reiterate that because NHC assigns intensity using 5-kt increments (and will be doing so for the foreseeable future), neither storms in the historical record nor any future storms would have their SSHWS category changed as a result of this adjustment. Changing the Category 4 range to 130-156 mph, 113-136 kt, and 209-251 km/h simply allows all unit conversions from knots to be done correctly and keep storms in the correct category, regardless of the units used. "