When the verb "break" refers to a record, it is normally used in a transitive way. Thus one normally says that a record "will be broken" (or has been broken) or that "X will break the record".
However, this is the kind of use where English tends to be flexible. Nouns get used as verbs, verbs as nouns, either as adjectives, and verbs are used intransitivly when they should technically be transitive. particularly in a news report, if someone writes:
That the record will break today is probable.
the meaning will be generally understood and few are likely to complain about the grammar. I would advise against using this construction, but it pretty clearly means the same thing as:
That the record will be broken today is probable.
and should be understood in that way.