Based on the wiki, it's possible but not guaranteed that Micah Parsons plays in Week 5 against the Bears.
Here's the timeline: Parsons suffered a torn left ACL plus a meniscus procedure in December 2025. He'll start the 2026 season on the PUP list, meaning he misses at least the first four games. Week 5 against Chicago is the earliest he could return — and the Packers are indeed targeting mid-October, which maps to that game (from the Micah Parsons page).
However, the wiki also notes he could need more time beyond Week 5, and even if activated, he may be on a snap count/limited ramp-up. So don't count on a full workload from him right away.