There seems to be a plethora of questions about risk of having an admission offer rescinded.
1. Academic risk of rescission:
College admission offers are typically conditional on completing the previously reported in-progress course work with sufficiently good academic performance, as verified on the final high school transcript. The following could result in risk of having the offer rescinded:
A. Schedule change, particularly to less demanding courses, that the college was not aware of before seeing the final high school transcript. Any schedule change after the applications are sent must be reported to the colleges. If an admission offer is already received, find out what the college will do about it.
B. If the college lists specific grade or GPA requirements for your in-progress courses, be sure to meet them.
C. If the college gives a vague "we expect you to maintain your academic performance" statement, then you do not really know what its exact criteria are. But it is reasonable to assume that, for your last semester (or year for colleges that have not seen your midyear grades) grades and GPA, you want to (1) avoid any D or F grades, (2) not have your GPA drop too far. "Too far" is something you do not know if the college does not say. But if your last semester GPA is the same or higher than your previous GPA, that should be ok. If it is only slightly lower (like 3.8 -> 3.7), the risk is low. But if it is a lot lower (like 3.8 -> below 3.0), the risk is higher.
If your grades or GPA are likely to be a problem, it is better to notify colleges earlier than later. If before May 1, you may want to try to find out which colleges that admitted you are more or less likely to rescind, so that you can include that consideration in your matriculation choice.
2. Other risk of rescission:
Typically, other risks of rescission involve conduct reasons, such as criminal conduct, or other things that schools tend to see as serious matters (like getting caught cheating).
Be careful what you put on social media or what you do that others can put on social media. Something that could be an embarrassment to you and the college if it hits the news would be risky (example: https://www.thecrimson.com/article/2017/6/5/2021-offers-rescinded-memes/