Hi,
according to Trevor, this was fixed in this CU: http://thesharepointfarm.com/2016/01/ms16-004-causes-a-typeerror-on-sharepoint-lists/ “The resolution is to apply the January 2016 Cumulative Update for SharePoint.”.
As for how we tell Microsoft about bugs, it would be nice to have a Connect site. I had a problem with a bug and I located it, found a workaround and don’t need support, but I would like to tell Microsoft about it. Using MS Support means signing an agreement, going through diagnostics with a support engineer on my production farm (I’m not too comfortable with that), because I can’t repro it on a test environment and paying money if it turns out to be a configuration/supportability issue instead of a bug. I agree that blog comments are not the place to submit bugs, but there’s lack of a better, place without major commitments (like Connect).