I have a kid who has ASD/Asperger's who attends a language immersion school and it's been pretty much a nonissue since his deficits don't affect language or academics. He excels at them in fact so the school's been a great fit overall with excellent SN services and a nurturing, inclusive environment.

Whether being bilingual is an issue would depend on the SN.

DH and I are bilingual but in different languages so in our family the only language we all have in common is English. LOL!

Nothing new, but still worth keeping in mind if you have a young child with potential impairments in a multilingual home.

My experience:
DC1 had developmental delays, and it affected his speech. The bilingualism nearly worked against us at Infants and Toddlers Early Intervention because first they told us they did not treat speech delays due to bilingualism, and later that they did treat speech delays due to developmental delays.
In the end, he received PT, OT and Speech because they could not fail to observe he was behind in everything (no eye contact, very little emotion, he could barely sit upright at 13 months, let alone crawl or stand).

We deliberately chose an inclusive ES with a good reputation for looking after its special needs population. Turns out they have a lot of foreigners as well, and know all about the confounding factors affecting speech development in bilingual children. Thank goodness!