Everything you save to your watchlist can sync to Google or Outlook as its own calendar. Saving stays free, syncing is Pro.
Your watchlist used to live only on Sync2Cal. Now it syncs like any other calendar, so the individual events you saved show up in Google Calendar or Outlook alongside everything else.
Saving events to your watchlist stays free. Syncing that watchlist to your calendar is part of Pro. Your saved events are kept either way, so if you upgrade later the list is exactly as you left it.