Sounds like it will be okay.
Yup, the internet is not a good place for nutrition advice... Dehydrated or not - if it's 30% dry matter, it's 30% dry matter. Way too high for Yorkies.
I used to get away with giving Ellie a lot of questionable things too - until one day she just couldn't take it anymore. Not worth the risk.
The vet could (and should) give you an rx food for now. Then you could talk about what to switch over to later.