SoundCloud Go and SoundCloud Pro Unlimited are two optional services offered by SoundCloud. You are not required to have SoundCloud Go or Pro Unlimited in order to monetize your SoundCloud account with Symphonic.
SoundCloud Go is a subscription service focused on SoundCloud listeners/consumers. It allows for offline streaming and the ability to remove ads while listening (this does not affect monetization, any playcounts from SoundCloud Go consumers are still paid out for monetization).
Any tracks appearing on your profile and/or available for that service will potentially show up or not show up in full unless you use SoundCloud Go as a subscriber.
SoundCloud Pro & Unlimited plans are focused mainly on creators of music - artists, songwriters, and labels. Pro allows for 360 minutes of uploads, Unlimited allows for an unlimited amount of uploads/minutes. Both Pro & Unlimited provide some statistics but Unlimited will provide the full breadth of SoundCloud reporting tools for those interested in monitoring their SoundCloud account.
SoundCloud Monetization via Symphonic is a service that allows you to earn royalties on the music you have on your profile. Both Free users and Go users accrue royalties for monetization (track play count is what matters, not how many ads are played), but they will be reported separately when the royalty reports come in.
In order to monetize, you must have your profile whitelisted through Symphonic, an agreement with Symphonic, and a spreadsheet filled out after Monetization is enabled. We can, in some cases, grant the ability for you to monetize directly on the Soundcloud profile as well but this is approved on a case by case basis.