Note that the cases still remain the same (the most notable being if threadInfo.name === '', then the expression if false is still chosen since '' is falsy).

Thanks for clarifying this.

return firstLine(
  threadInfo.name ?? robotextName(threadInfo, viewerID, userInfos),
);

wouldn't work because it only cares if the LHS is null or undefined. But, both the ternary and || operator only care about "truthiness." And the empty string is "falsey," so this looks good!