I edited the tail end of my previous comment to touch on this, which is to say that omitting the direct object typically involves using intransitive instead of

I edited the tail end of my previous comment to touch on this, which is to say that omitting the direct object typically involves using intransitive instead of transitive. For example, the intransitive "today I ate" instead of the transitive "today I ate pie" leaves you guessing what I ate. The verb "surprise" does seem to have an intransitive syntax per https://www.merriam-webster.com/dictionary/surprise https://www.merriam-webster.com/dictionary/surprise which gives a similar sentiment as "surprisingly."