Trips assigned to service calendars with occasional service (i.e. anything other than Mon-Fri, Sat/Sun, Sat, or Sun) do not currently display properly in the new Google Maps interface. For example, if a trip is set to a M/W/F service calendar, and a user plans a trip on Tuesday, Google Maps will return a trip without any additional note. This may result in riders being led to believe that this same trip is available T/Th even though it is not.
Google is aware of this issue but has not provided a timeline for its correction.
Screenshots below is for Columbia Area Transit (Hood River County Transportation District) in Oregon, captured 6-August-2015. Link to query in Google Maps.
Users can see a warning in the "schedule explorer" view.