Points expiration was temporarily paused during the pandemic in (if I remember well) 2021 and 2022. That is no longer the case and as noted above they will expire after 24 consecutive months of no activity. The 24-month time period was actually introduced in 2023 - before that it was 15 months.
For reference:
https://www.hilton.com/en/hilton-hon...policy-changes
Points Expiration Policy
What is the Point Expiration Policy?
We have extended the amount of time required to keep your Hilton Honors account active from 15 to 24 months. Members must keep their Hilton Honors account active in order to keep their Hilton Honors Points. Under the new policy, if your account is inactive for 24 consecutive months, your total Point balance will expire.
Points Expiration Activity
Keep your Hilton Honors account active to avoid your Points expiring: simply stay at any hotel in the Hilton Portfolio, earn points with a Hilton Honors credit card, earn or redeem Points with any Hilton Honors partner, buy Points or donate Points, or register for a Hilton Honors promotion.