It depends on how often that person visits HN, how busy is their "threads" timeline and how deeply they go into it. Then, finally, whether or not your comment requires or provokes a response.
Your reply actually made me curious and I logged into an old Hacker News account that I hadn’t used in a few years. Hundreds of comments on that account, many that had a very positive responses (thousands of total points). Yet not a single point was given since I switched accounts, likely because close to no one has read any of those comments since they were made.
On web forums it’s not unusual for me to get replies and reactions for comments that were made a decade ago.
That can be a problem, which is why some web forums lock threads against necroposting.
HN also doesn't allow necroposting. If you view some months-old posting, the reply link won't be there.