What is North Korea's end game with some of these new weapons? Given that they have nuclear weapons along with a number of growing delivery platforms that having increasing survivability what exactly are they hoping to achieve through further military modernization?
they're learning from the Ukraine conflict. It is found that drones are much more cost effective than manned aircraft and still work in an environment of air inferiority.
They need a HALE drone to long term patrol and map the areas around North Korean border, Yellow Sea, Sea of Japan. This is valuable data that is not only useful for themselves but can be sold to China and Russia (more like a subsidy for North Korea tbh but at least its nominally for a service, which will motivate them to do better). It gives a much closer look at South Korean military positions along the DMZ and in the southern Sea of Japan than China or Russia can get on their own without patrolling inside North Korea, which has potential political implications.
They need a MALE drone for both light patrol duties and for deep artillery recon, CAS and strike if any aggressors attack North Korea. Though not useful in a full conflict with South Korea or the US, they can still be used just like the TB-2 was to inflict losses on unprepared invasions that outrun their air defense, forcing the entire enemy invasion to slow down to the pace of air defense only and giving ATGMs, artillery, etc the time they need to set up.
They need loitering munitions, both airborne and seaborne, that again have been proven to work as both tactical and strategic strike.
Basically, they're adding the lessons of Ukraine to their modernization, which shows their capability to rapidly adapt when a clear direction is given.