Yes. You will able to access your saved files in New PicMonkey Hub where they will still be multi-layered.
You'll notice that they are marked with "OLD" which just lets you know that they were created in Old PicMonkey. When you open the image in New PicMonkey, you’ll be prompted to give it a name.
Note: If you start a new design in New PicMonkey and then try to open it in Old PicMonkey, it will NOT remain multi-layered there.
Note: In New PicMonkey, you no longer need to click “Save”, instead all your work automatically saves to Hub.
Learn more: What is Hub?