There’s an updated (December 2021) Power Platform Licensing Guide which includes two changes. Firstly, Power Apps users now have the ability to create, read, update and delete Dynamics 365 Field Service work orders (see page 5). Secondly, the Power Apps per App and per User licences now include 250 and 500 AI Builder service credits respectively (see pages 4 and 5).
Download this updated guide here: https://bit.ly/3omxI52.