There are diminishing returns to further optimization of lower-climate-impact meat sources. Look at greenhouse gas emissions per 100 grams of protein in various foods:

https://ourworldindata.org/grapher/ghg-per-protein-poore

Beef is really high at 48.89 kg CO2e, but pork is only 7.6 kg CO2e. Farmed fish is 5.98 and poultry is 5.7. If you can get people to switch from high-climate-impact meat to low-climate-impact meat, you've already reaped most of the possible climate gains from dietary change. To meet a given protein consumption target, you cut 88% of the emissions by getting protein from chicken instead of beef. Trying to get people to eat unfamiliar and potentially "icky" protein sources after they've already switched to chicken can only produce minor gains.

Though most people are reacting to the headline about how humans could eat maggots, the article says that these maggots are actually being fed to chickens, farmed fish, and other animals. That approach reduces waste streams, slightly reduces the already-modest climate impact of farmed fish and poultry, and doesn't have the enormous uphill battle toward regulatory and consumer acceptance that direct human consumption would face.