ModusToolbox is newer software environment by Cypress, giving you flexibility of developing your applications with customizable BSPs, selection of libraries as per your need. New platforms and also Cypress Bluetooth products will be supported in ModusToolbox now onwards. There are many extra features also added like cloud support.
To develop an application using CYBT-413055, I would suggest you to go with ModusToolbox. As we will be providing updates & newer features in MTB (not WICED SDK), it will be convenient for you to develop your application in future.