This is a subjective market, so I won't give explicit resolution criteria. But here are a few examples of things that would make a positive resolution likely:
If the Centre for Effective Altruism still exists in a meaningful state
If the EA Forum is still active and receives regular posts
If surveys about effective altruism indicate that there are a meaningful number of EA-identifying people
If I personally know 20+ people that actively identify as effective altruists
Any other indicator that there are thousands of EA-identifying people
An active and thriving community that is essentially the same as the current EA movement but has changed its name for whatever reason
A few things that would not qualify for a positive resolution:
Those few weird friends that still cling to EA labels even though most everyone has moved on
A movement that advocates for fundamentally different principles from these under the same name of Effective Altruism
Happy to add other examples under these two lists if they come up in the comments.
@L I wouldn't interpret it as a bar for a positive resolution. It's possible I know 20 people that identify as EAs but still don't consider the movement to exist anymore. But considering that, right now, I don't think I personally know more than 10 people that would identify as EAs, if I know 20 or more I do think that makes it likely that the movement still exists