I noticed that several high reputation and medium reputation members who used to be regular users of ELU for over 3 years have not posted anything for over 6 months. I don't want to name names but they have made major contributions here. Frankly I worry that something happened to them, though that is unlikely in the vast majority of such cases. Participating here is of course purely their own decision, but I did notice a few such users become 'active again' after a long absence.
So should the moderator team try to reach out to them via email on behalf of the community (as some other websites tend to do) and if so, what would be an appropriately short generic message?
Updated on 7th September 2017:
May I expand on my question using these comments I posted in reply to pertinent queries from members here:
The user profile can easily show the user pattern that led to inactivity. One pattern is typical -- the frequency of posting falls off slowly before no more posts since a certain date. This can be indeed be interpreted as a being a gradual loss of interest in most cases (...)
The other pattern is more perplexing: a more or less abrupt cessation of posting by a previously active member. While I shouldn't suggest anything that goes against established SE policy, these people have been our long-term collaborators in this project...
My question to the current members and moderators was simply "don't we care that senior members have left the site? Don't we want to know why, if possible? If it was your co-workers at your so-called real-life office that disappeared, will you ignore like this..."
The site administrators have the contact details such as email id of all members (...) if the moderators at ELU think it is a good idea (based on the feedback to this question) they can easily send them a pre-formatted generic email such as "dear member so-and-so: this is moderator A & you last posted at ELU over 6 months ago. You have been a valuable contributor here and we should greatly welcome your continued participation. At the very least please consider explaining in an email the reasons you are no longer active on ELU so that we might take steps to improve user experience here."
Let's assume that only 20% of former regular users even respond to such a message from a moderator with a return email giving the reasons for leaving the site (...) that's still significant and valuable feedback for moderators to understand the possible problems and take any necessary steps to improve the user experience.On the other hand, the way a few members have responded here, "let them leave - they must have their reasons - why should we care if they leave: they have contributed and the site doesn't need them any more (paraphrase)" doesn't seem to be a constructive attitude.
[to sum up] I have simply raised the issue of absent regulars here; and what to do about it (if at all to do something) should be decided purely on the basis of community consensus as expressed by members here.