Metalizer and Chopper are still included with Cubase. They’re even still using the old interface. (probably going to be updated very soon)
As for Symphonic, use these stock plugins as a send: AutoPan -> Chorus or StudioChorus using non-subtle settings, OR StereoEnhancer -> Chorus or StudioChorus (alternatively, use StereoEnhancer as an insert and use the Color and Delay knobs instead of chorus)
Symphonic could create either an autopan or stereo enhancement effect (not both at the same time). Autopan is only used if tempo sync is activated.
Symphonic’s Stereo Basis knob controlled the autopan “width” or the stereo enhancement effect. When using the stereo enhancer, 50% was the same as original, higher values made things sound wider and lower values collapsed the sound to mono.
The AutoPan effect was updated and massively improved in Cubase 9, while the StereoEnhancer is basically black magic compared to what Symphonic was able to do. You should be able to make your old project sound much better with the right settings.