Typically not. Google as an example: the transformer paper (Vaswani et al., 2017) was arxiv'd in June of 2017, and NeurIPS (the conference in which it was published) was in December of that year; BERT (Devlin et al., 2019) was similarly arxiv'd before publication.

Recent announcements from companies tend to be even more divorced from conference dates, as they release anemic "Technical Reports" that largely wouldn't pass muster in a peer review.