So first, in order to invoke "stay put," you have to file some type of dispute resolution. Either mediation or due process. You don't just declare "stay put" and nothing changes. (otherwise that's what many parents would do)
Def time to read your procedural safeguards booklet and review your options.
If you disagree with the eval results, you can request an IEE. That will also be in your procedural safeguards.
IEPs are NOT just for academics, however you may not have enough data in other areas to warrant one. If they only assessed in academics and he's "fine" there, then you have to get other data.
As far as the pronoun thing, that alone is not enough to warrant an IEP. However it can be indicative of other issues, such as possibly pragmatics.
Based on what you posted here, he was really only evaluated in speech and if there are other concerns, you have to request that.