I don't think it will affect it. My friend just got his citizenship interview scheduled (which beats the average processing time for his area by 2 months) and his wife's I-130 got approved few days ago as well. And this is after the priority date became current for Spouses for Permanent Residents (though this was sent out before that) which surely increased the workload for USCIS.

The approvals are still coming and the citizenship interviews are still being given. Business as usual.

USCIS is self funded so the shut down should have no bearing on processing times.