A junior or mid-level dev may often think that coding is progress and having more and more complex or craftsman-like solutions is the goal, because they think development is all about coding.
In reality, having less to maintain while still providing what’s needed is what’s best. This is the way.
Sometimes solutions aren’t obvious. You’re right that a decision should have been made, but maybe the decision was to wait and see.
Maybe your TL is too indecisive and not timely enough, or maybe they aren’t the problem.
If it continues and you think that it’s an ongoing problem that isn’t benefiting your organization, talk about it with the TL directly. Listen to them.
Finally, if that doesn’t work, talk to their supervisor. Tell them a lot of dev time is being wasted. But only after you do the rest and think through it.
Remember what Douglas Adams said: “I love deadlines. I like the whooshing sound they make as they fly by.” If it’s contractual, it may be important, though, in which case you should bring it up with the TL.
Finally, could this have been designed better and more comprehensively up front? Or does your team not do that well?