ezo
Get off my lawn!
Not really.You have it backwars. It is specific overiding general. Invisibility comes with the specific mechanism that causes disadvantage/advantage regardless of being seen or unseen. It overrides the general rule for unseen/seen attackers (or makes it moot).
If it did not override the general rule that bullet would not be in there and only the first one would or it would be worded differently, to reference the unseen/seen section. RAW the second bullet means the advantage/disadvantage applies whether or not the attacker is unseen.
Look at it this way - The wording in the invisible condition is similar to the wording in the restrained condition. Restrained causes advantage/disadvantage whether or not you can see the target. Same with the invisible condition.
What most people fail to realize is several of the conditions have a defining part which, if untrue, means the condition is removed. Invisibility is one of these, just like Blinded (you cannot see), Deafened (you cannot hear), Prone (you can only crawl), and so on. For Invisibility, it is you are impossible to see (without magical means, etc.). The difference being the defining parts of all the other conditions are negative, as where for Invisibility is it (generally) positive.
Unfortunately for Invisibility, it is the only beneficial condition in the game (despite that the PHB says there are "a few"). It is also the only condition which is dependent upon the interaction between the two (invisible creature and possible viewer).
The second bullet is simply there for completeness, not as an independent benefit. Consider every other condition, every point is either true, or the entire condition is negated. A blinded creature that can now "see" (negating the first bullet), does not continue to have the second bullet affecting them.
Another way to realize this is to ask yourself why are the later bullet points included? Because they are the results of the first, of the condition being valid, otherwise they would not affect the creature with the condition.
And features such as Truesight, are even more specific in overriding a feature like Invisibility.