If you've used the font in a design, to make a PDF with embedded font, or a raster image like a PNG, it still works as before. But if you want to edit the design (for example in InDesign, Photoshop or Premiere Pro) you just won't have that font. You'd have to find it and, if available that way, license it for download and use for you.
Third party clients don't really figure in this; they can use your generated work as before, and never had any need of the font license. You could never share the fonts with them, but if they had Creative Cloud they could collaborate with the same fonts. Now they would need to purchase their own copies.
From a personal perspective, for work with a long life and development process, I'm not sure I'd choose Adobe fonts, since we've seen they can disappear, and this may have design and cost implications for projects.