I haven't used Captivate since Flash was still a thing.
I am just curious, why is SWF still showing up under Project Info > Preferences > Project > Size and Quality ?
I confirmed that there are no SWF files in the final published zip file. Just curious.
SWF is still one of the outputs to which Captivate can publish. Until Captivate removes that option entirely, you're still going to need those Preference options.
Still many companies stick with very old versions of rowsers and/or LMS which only support SWF output.
BTW Project info offers you the functionality to have an estimation of the size of the output, both for SWF and for HTML5 if you talki about a non-responsive project. Very useful!