Hi, Shawn!
I am sure that you will still be allowed to use your sit and stand as a wheelchair and stroller combo. while using the new
Disability Access Service Card. According to the Frequently Asked Questions post I've linked here, nothing has changed regarding the equipment Guests choose to use to make their touring of Walt Disney World more comfortable. Instead, the
timing of Guests' return to various attractions will be different. Should you need additional assistance, be sure to speak with a Cast Member at Guest Relations, just as you would have done previously. They are there to provide you with the assistance you need so that your entire family will have a magical visit.
In short, you'll have no issues with using the sit and stand in conjunction with the new DAS Card, Shawn. No worries there!
Have a magical trip! Be sure to continue sending your questions our way as you plan yet another pixie dusted visit to Walt Disney World! We love to help!