Perhaps Titled or someone more read on the laws can chime in on this...
I'm now reading that perhaps these cases are not being heard at this hour for a simple reason...
The votes that were done today by the states' electors will be tallied before both houses of Congress on January 8th, which will make the projected electoral votes official. (source: Wikipedia)
As far as the two applications that SCOTUS has thus far denied (Donofrio and Wrotnowski), I don't think that could have had anything to do with their being denied. In my opinion, those applications were non-starters. First, there didn't appear to be any legal principle on which to grant cert in those cases (e.g. a decision by a lower court that conflicted with other decisions by lower courts or with a previous decision by SCOTUS, or a decision by a lower court on an unresolved question of law that needs to be settled by SCOTUS). Second, the arguments made in those two applications were very weak, and I suspect the Court didn't feel they needed to further clarify the issues addressed in those applications. Essentially, the argument by Donofrio and Wrotnowski was that the phrase 'natural born citizen', when used in the Constitution, can only be interpreted to mean someone who is born on US soil AND is born to two US citizens. There's just not much evidence to justify that conclusion, and SCOTUS has already ruled several times that the Constitution grants Congress the authority to make laws that govern Naturalization (i.e. Citizenship).
As far as Berg's petition goes, while it is possible that what you are referring to could be an issue that the Court considers, it doesn't seem likely that it would affect the decision to grant or deny the petition. Conceivably, the Court could believe that the question of standing technically changes based on the timing of certain events; however, such issues would only seem to come into play if they were actually 'hearing' the merits of the case - not when deciding on whether or not to 'hear' it. Furthermore, Berg's petition isn't likely to be considered before January 9th, so it will be a mute point anyway.
I still don't think that Berg's petition will be granted, but I do think it is possible that it will for this reason - the Court may see a need to settle some Constitutional questions that are likely to be at issue going forward:
(1) Does the US Constitution imply an inherent obligation on the part of anyone to verify the Constitutional qualifications of candidates to national office?
(2) If so, then whom does it place that obligation on? Does the 20th Amendment imply that Congress has just such an obligation when it comes to Presidential candidates?
(3) If it doesn't place these obligations on an entity certain (and even if it does), then whom has standing, under the Constitution, to challenge the qualifications of a candidate and/or an elected official and/or a serving official? Surely Constitutional requirements are meaningless if no one has the responsibility of verifying that they have been met AND no one has standing to question whether or not they have.
That last question gives the Court a very clear legal principle on which to grant Berg's petition in specific, should they find the need to answer it. The more I think about it, the less it would shock me if they did grant him review on a writ of cert, regardless of the merits of the birth certificate issue.
I will say that I give this Court the benefit of the doubt. At the end of the day, I believe they will decide Berg's petition on the basis of the same standards that they apply in the thousands of other cases that come before them. For the most part, the Court's history doesn't suggest to me that they would shy away from a controversial issue that they thought was in need of resolution, just because they were scared of the consequences. That's just my opinion and I certainly hope I'm right.