Basically...yes. From what I've seen, most hardy trees can handle a light freeze as they are leafing out. Trees in the landscape are exposed to light freezing conditions during leaf out
most springs and they do fine.
Now, the trick is...I've found temps down to 30, 29 F are usually OK, especially if only for a couple of hours late at night. However...the problem is you don't know if the
temp is going to stop at 30 or 29 or drift down to 25 or 24. Once you get down into the mid 20s new growth can be killed completely. We had that happen a few years ago. It was the really
warm winter and everything was into growth by March. Then we had a hard freeze down to about 22 F and the new growth on everything (yard trees, not bonsai which were brought in) was killed.
Trees sprouted again and were growing strongly, then we had another hard freeze down to around 22 F in mid or late April. All new growth was completely killed back a second time. Some weak/young
plants in the growing bed didn't make it through that double whammy. Most survived and put out a third growth flush.
You have to know your trees and your microclimate. Clear skies/light winds/low dewpoint increase the risk of temperatures dropping colder than expected. If the dewpoint is 30 F chances are the
air temperature won't drop much below 30 (it can, but usually won't).
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