Ola Index and Update stats
The parameters you're looking at are only used if indexes are reorganized.

Depending on the level of fragmentation involved, which you provide when you run the task, the IndexOptimize stored procedure will either rebuild indexes (which do not require statistics updates), or reorganize (which do require statistics updates).

There is a third scenario, where you can only update statistics, using the following code (from Ola's site):

EXECUTE dbo.IndexOptimize
@Databases = 'USER_DATABASES',
@FragmentationLow = NULL,
@FragmentationMedium = NULL,
@FragmentationHigh = NULL,
@UpdateStatistics = 'ALL',
@OnlyModifiedStatistics = 'Y';


Note that the Fragmentation options are explicitly set to NULL in this scenario.