This is a good site, used for business communications. If you trust the users of the site you are linked too then you should be OK, BUT Google does warn that there are SOME links, namely intercomassets.com, which link to malware sites that could download malware or pups onto your system. As a result, marked this site with caution (More to do with the fact that the target is intercomassets.com, which users might reasonably expect to be safe.
This site is used as a messaging service by other websites. They provide services to communicate with users by messaging and email. The site could therfore be used for suspicious activity but it is not intended as such.
If you trust the website that uses the services of intercom.io then it should be ok.