alidator.Suggestive API was created in year 2002 to be able to create validators that propose corrections for invalid values. During the years this idea has prooved itself to be inpractical - (almost certainly) no-one has ever used this API. As you say - even the base framework (AbstractField) does not support it.
We can make exception for backwards compatibility changes rule in this case and just drop the API as it (almost certainly) would not affect anyone.