Cherry and Pale Oak Saplings, as well as mangrove propagules don’t spawn in bonus chests.
To replicate just create a world and enable bonus chests.
MCPE-227788
1.19+ Saplings not appearing in bonus chests
Resolved
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There are some kinds of saplings that do appear in Bonus Chests, though not all of them or all the time.
Please provide an official source that shows that the mentioned items should appear in Bonus Chests for 1.20 or later versions.