A.I.
Sounds like you're doing the right thing with EI - I would say let the speech folks make their diagnosis on whether he has any physical problems with his mouth (for eating). If not, I don't know, I wouldn't worry too much yet. My daughter is just 12 months and she's eating the same way. But then 3-4 days ago she just started refusing the purees and wants to finger feed everything. She still won't eat pieces of green beans, peas, etc - she's not big on vegetables. But the finger food fruits and grains are going over well. I think she's just 'ready' all the sudden.
I think, barring any problems with ST, your son will just move the finger foods when he's ready. Does daycare refuse to feed him purees? If not, I'd just keep offering finger foods for exposure and then make sure he gets enough nutrition with purees. When he's ready, he'll be ready. And of course ST will give you tips on how to encourage him.
If this helps any, i've had some experience with this. My oldest child had the milk/soy protein allergies (though he outgrew his at age 1) and was in ST and physical therapy due to multiple heart surgeries until 2 1/2. I found that while he was catching up/ mastering one skill, he didn't make progress in others. For instance while he was really working on gross motor skills (ie walking), he wasn't progressing at all with speech. But he caught up with everything by 2 1/2. So perhaps your son developmentally is focusing so much on speech that he's not focusing on feeding right now.
I don't really know - I'm not a doctor or therapist so take all of this with a grain of salt!!!
Feel free to contact me directly if you'd like to email more.
Good luck!
A.