Never been able to find an acquisition forecast for USSOCOM, just a redirect to fbo.gov with current solicitations.

Published department / agency forecasts vary. Some provide extensive guidance, others barely anything. The website with links to individual agency forecasts is below (and then the links are not always to the direct area of agency forecasts, just the main website, so you need to search "procurement and / or contracting and / or acquisition forecast").

https://acquisition.gov/procurement-forecasts

DoD has links to various commands / organizations / agencies procurement forecasts within the department (vary in detail, usefulness)

https://business.defense.gov/Small-Business/Acquisition-Forecasts/

DHS actually has a good forecasting list by DHS agency, including what contract vehicles (e.g. OASIS) are being used for various contracts.

https://apfs.dhs.gov/

GSA also has a good forecasting tool that you can search by various criteria, e.g. place of performance, projected solicitation quarter etc.

https://hallways.cap.gsa.gov/app/#/x/forecast-of-contracting-opportunities
Forecasts and more