The new rules make it mandatory for all motorcycles to have a grab rail and footrests for pillion if the vehicle is intended to carry two passengers, including the rider. Both the parts must meet requirements specified by AIS (Automotive Industry Standards) 148:2018 till the corresponding BIS specifications are notified. All motorcycles must also come with a protective device covering not less than half of the rear wheel to prevent the clothes of the pillion rider from being entangled in the wheel
Below is an illustration from AIS 148:2018 which is the reference standard given in the act.
The Act update just mandates a foot rest for the pillion rider. It doesn’t mention that a side saddle footrest is also mandatory. 450 and the 450X both have a footrest. I don’t see anything changing on either of them because of this new update to the MV Act.
Depending on the details of the requirement what might change is a rear wheel cover as it requires atleast half of the rear wheel to be covered.