It almost certainly varies between jurisdictions. However, a few minutes ago I looked it up the proposed law in Washington[^1] for this story, and it does actually require reporting of all past cases of child abuse for all groups listed (therapists and other professionals, and now priests also).

To be clear, it's the time that varies, almost everywhere has laws requiring some level of mandatory reporting. But, for example, the federal definition[^2] does not require reporting of child abuse cases in the distant past (my emphasis):

What Constitutes Child Abuse and Neglect?

At the federal level, the Child Abuse Prevention and Treatment Act (CAPTA) provides a minimum definition of child abuse and neglect. It is defined as, “any recent act or failure to act on the part of a parent or caretaker which results in death, serious physical or emotional harm, sexual abuse or exploitation…or an act or failure to act which presents an imminent risk of serious harm.”

The key part is that it only covers recent harm and imminent risk. This is the baseline that's pretty much universal, but it seems many, or at least some, states have laws that go further and require all reporting. The Washington state law[^1] is summarised as:

When [any member of these groups] has reasonable cause to believe that a child has suffered abuse or neglect, he or she shall report such incident, or cause a report to be made, to the proper law enforcement agency or to the department

[^{1]: https://app.leg.wa.gov/billsummary/?BillNumber=5375&Year=2025 - direct pdf link: https://lawfilesext.leg.wa.gov/biennium/2025-26/Pdf/Bills/Session%20Laws/Senate/5375.SL.pdf?q=20250510110254 (see Sec. 2. page 6) [}2]: https://govfacts.org/federal/hhs/reporting-suspected-child-abuse-or-neglect-a-guide-for-action/