Modern slide films DO have some exposure latitude (btw, Kodachrome is not modern; by modern I mean Velvia, Provia, Astia, Sensia, Kodak E-100/200). In general 1/2 stop overexposure will not completely blow out the highlights. So, as long as the camera meter is calibrated within 1/3 stops and you remember the general limitation of center-weighted metering, there should be no general problems.
However, with center-weighted metering and slide film you will always have consider the exposure carefully, unless the lighting is very even, and apply exposure compensation accordingly. If you don't have time to do that then bracketing is a good way to get at least one properly exposed shot.