Were these Jewish believers told to quit temple worship and stop legalism?
No. These Jewish believers were not told to quit temple worship or stop legalism. They continued maintaining their Judaism while also recognizing that Jesus was the Christ. Ananias was a believing but law-keeping Jew, and no one had yet told him he was not under Law but under grace.
Les explains from Acts 22 that Ananias was a devout man according to the Word and a Jew. He was a believing but law-keeping Jew. No one had yet told Ananias, “You’re not under the Law, you’re under grace.” Likewise, no one had told these Jewish believers to quit temple worship or stop legalism. They maintained their Judaism while recognizing that Jesus was the Christ. Paul recounts this Damascus experience in the first person many years later to the multitude of Jews.