The Oregon Trail Memorial Association attempted to boost sales of its Half Dollars by linking certain releases to current events (e.g., 1933 Century of Progress International Exposition) and/or historical events/anniversaries (e.g., 1934 Fort Hall/Fort Laramie/Jason Lee Centennial). (I've posted about these "anniversary" issues here:
1926-39 Oregon Trail Memorial - 1934 Oregon Trail Centennials.
I haven't seen similar advertising activities for historical anniversaries associated with events connected to Daniel Boone - was the Daniel Boone Bicentennial Commission "asleep at the wheel"?
I can think of two particular events the anniversaries of which could have worked nicely for the Boone half dollar, and tied in directly to the coin's reverse design elements.
The first would have been the 160th anniversary of Daniel Boone's creating the Wilderness Road - under contract to the Transylvania Company out of North Carolina - which linked eastern settlements to areas west of the Appalachian Mountains via the Cumberland Gap. The Wilderness Road soon became the primary route for those looking to travel to and/or settle in the west; it was a key component of Kentucky's settlement.
The reverse of the Boone half dollar presents the sun rising over the Cumberland Mountains, a part of the Appalachian Mountains range. As noted above, Boone blazed a trail through these mountains via the Cumberland Gap.
1935/34 Daniel Boone Birth Bicentennial Half Dollar

Another workable anniversary would have been the 160th Anniversary of the 1778 successful defense of Fort Boonesborough from the attack and nine-day siege levied against it by Chief Black Fish and his Shawnee warriors.
The reverse of the Boone half dollar depicts - center stage - standing figures of Boone and Chief Black Fish in pseudo-negotiations over the surrender of the Fort - Boone is believed to have been using the "negotiations" as a delay tactic in hope that his reinforcements would arrive; the Fort defenders were outnumbered ~400 to ~60. The design presents a portion of Fort Boonesborough in the background to the left of the figures.
1938 Daniel Boone Bicentennial Half Dollar
(Image Source: Heritage Auctions.)Close-up View of Boone Half Dollar Reverse Showing Fort Booneborough (Left) and Cumberland Mountains (Right)

I realize a "160th Anniversary" doesn't have the cachet of a 150th or 200th, but it is certainly a toutable milestone when looking to market your commemorative coins! Opportunity missed?
For other of my posts about commemorative coins and medals, including other stories about the Daniel Boone half dollars, see:
Commems Collection.