Wiktionary says both meanings are acceptable.
reform (third-person singular simple present reforms, present participle reforming, simple past and past participle reformed)
- To put into a new and improved form or condition; to restore to a former good state, or bring from bad to good; to change from worse to better; to amend; to correct.
- To return to a good state; to amend or correct one's own character or habits; as, a person of settled habits of vice will seldom reform.
- (transitive, intransitive) To form again or in a new configuration.
I can't say Wiktionary is the go-to dictionary when you need language reference, but it is indeed a good source for colloquial use, that both senses of "reform" should be easily comprehensible and discernable as long as it is not very formal English where high language accuracy would be expected.
Conversely though, major dictionaries such as Merriam-Webster, Dictionary.com and Oxford Dictionaries only give the "social reform" sense. Google Dictionary gives the same result. This is in fact the most established meaning of the word, while the "form again" meaning, which is now often encountered with the advancement of science and technology, comes from the addition of the prefix "re-" with the word "form". Logical reasoning tells people that this is the right word for "form again", but in order to avoid confusion with the main meaning of the word(which is why we need to follow standards), writers leave the hyphen in place so as to make it clear that this word is constructed ad hoc and has the plainest meaning unaffected by historical language use note1.
Note1: words obtain more sophisticated meaning over time, because of patterns in word choice. E.g. a person would choose the word incredible for something that is so amazing it is hard to believe, and pass the usage pattern on to others in their circle. Over time amazing became the main, most used meaning of the word incredible, instead of its original sense of low credibility. Likewise, though I don't have proof, reform likely got its meaning from re-form, which can bear a restructure meaning, and later picking up additional details such as for good to get its present meaning of to change for the better.