The word has multiple pronunciations, as shown by the multiple transcriptions in the dictionaries that you cite: Merriam Webster lists "\ˈwäft, ˈwaft" and Cambridge lists "US /wɑft, wæft/" in its dictionary of American English and "UK /wɒft/ US /wɑːft/" in its dictionary of British English.
Using raft and soft as examples is problematic because both of these words have multiple pronunciations. I'll use other words with more stable vowels as references (unfortunately, they don't rhyme). The first pronunciation listed for the US, /wɑft/, has the vowel found in the word lot. The second pronunciation listed for the US, /wæft/, has the vowel found in the word trap.
I don't know of any general opinions about which pronunciation is more "correct", but if one was widely considered incorrect, the dictionary would probably mark it with an obelus, as in Merriam-Webster's entry for mischievous "\ˈmis-chə-vəs, ˈmish-; ÷mis-ˈchē-vē-əs, mish-", or a note, as in Merriam-Webster's entry for ask "\ˈask, ˈäsk; dial ˈaks\." I checked Charles Harrington Elster's Big Book of Beastly Mispronunciations (an amusing, and sometimes informative work, but definitely not a good reference for impartial evaluation of pronunciation variants) and even Elster accepts either "WAHFT or WAFT." In my experience, he's a good example of the kind of person who thinks dictionaries aren't prescriptive enough, so if there was any common prescription for which one to use I'd expect him to mention it.
An interesting side point: neither of the American pronunciations seems to me like quite what I would expect based on the spelling. I was expecting */wɔːft/ (with the vowel of soft, for people who have a different vowel in that word from the vowel in lot) to be a possible pronunciation, but I haven't found any dictionary that lists it. I wonder if there's anyone who uses it anyway. Another thing I learned is that most Americans use the lot vowel in waffle, although Merriam-Webster lists a second pronunciation with the soft vowel.