Scraping of data that individuals posted in one context, for one purpose, will mean that the scraper intends to use the content in a way that the poster did not intend.
There is no consent for this use.
Scraping of personal information (including personal updates) almost always happens without consent and without compassion for individuals and their autonomy.
The fact that the information is public and available has nothing to do with consent for any use that the scraping party desires.
Whether or not that use is considered benevolent and harmless by the scraping party does not matter.
Whether or not a majority of people appear to approve of the scraping does not matter.
Whether or not there is an option to opt out (after the fact) does not matter.
Scraping without consent is one way that disenfranchised and vulnerable individuals are harmed and forced to leave online spaces that are of value to them.