I don't understand that comment?
For the case right now, all mechanics improvements are a free update, and the paid(-free-for-who-owns-the-game-now) DLC only is CIV/Leaders/Wonders content.
I think that part of the conflict here (not necessarily in regards to you specifically) is that the comment can be interpreted in two ways, depending on if "of course" is read as applying to the present situation or to the future situation. The former, "I knew this was going to happen," comes across as more sarcastic and would be based on a misunderstanding, but the latter, "we must consider that this will happen," is asserting that although some complaints with the game are going to be settled for free, there will likely be aspects that will only be "fixed" at an additional price.
I cannot speak for them, of course, but I am inclined to believe that the latter was indeed their intention, and am also sympathetic to it as an argument. After all, if we're framing patches such as this as working towards completing an unfinished game, that implies that any underbaked mechanics are owed to us in their finished state, are something we paid for but have not yet received. Thus, for a feature requiring refurbishment to only get it with an extra payment is shirking that obligation. It all comes down to something really hard to define, which is what exactly counts as "missing" from the base game.
For instance, if the current religion system is, by your personal model, less than what
should be there, more
should be added without an additional charge. Furthermore, if you personally hold that better naval combat as well as many other things
should be there, then the addition of better naval combat is a mere step towards fulfilling a larger obligation, and if you believe that some parts of that larger obligation (again, devised by your own methods derived from your own values) are not going to be fulfilled, the situation is that you have only been given part of what you are owed and are not expecting to receive the rest, justifying a lack of celebration or optimism.
I think that is the thought process occurring here, and even though I'm not sure that I agree with it (either on the grounds of what is "owed" or on the required assumption that a large amount of current complaints will only be fixed come DLC), I think it calls attention to some very important questions regarding the treatment of additional content for Civ VII.