You need to check both that its valid and that its still open. Many times I've seen TODOs with issues in code where the issue was closed. Since nothing gates the Issues being closed, you've now broken CI by closing them.
Say you do get past that hurdle, you've added friction to the process of managing the backlog because the code now needs to be updated when Issues are rejected.
The sad part? With almost 10 years on a 20-30 year old code base with many millions of lines of code that are littered with TODOs, I don't think the presence of a TODO was ever helpful when we decided to actually fix an issue.