Include in Forecast Checkbox in Opportunity Form and Records is Missing

Consider the following:

 

• When creating a new Opportunity record, there is no Include in Forecast check box in the form and there is now a Forecast type field where you can select a forecast category – Omitted, Worst Case, Most Likely or Upside

• When checking previously created Opportunity records, there is no Include in Forecast check box and there is now a Forecast type field with a value equal to Setup > Sales > Sales Preferences > Forecasts > Default Forecast Type

• There is now an option to set forecast categories when navigating to Setup > Sales > Sales Preferences > Forecasts > Low Forecast Name, Medium Forecast Name, High Forecast Name

 

The given scenario happens when Advanced Forecasting is enabled. To verify this, navigate to Setup > Company > Setup Tasks > Enable Features > CRM > Advanced Forecasting = True