"Private" EF Masses: Must they be kept secret?

A moving item from Ttony of The Muniment Room -
http://ttonys-blog.blogspot.com/2009/06/serving-tlm.html
- about his experience of serving a private Mass in the Extraordinary Form. His posting deals mainly with the intense experience of these encounters with God; but his first paragraph has the following details: the priest "is not allowed to celebrate it publically"... "the Mass is not public or announced" ... "invitations are not a way of making these private Masses public or regular celebrations" ...

Oh, how that resonated! There are fewer priests, and fewer scheduled (that is, "public") Masses; therefore if a priest decides to offer in addition a "private" Mass in the EF, it is surely a bonus for the parish. There seems no reason at all why knowledge of these Masses should be kept from the faithful of the area.

I am aware of one such Mass. There is a steady congregation; but an item in the newsletter to inform the rest of the parish about the Mass's existence cannot be considered, it is said, without careful thought and consultation.

I am concerned that if "private" is being over-interpreted as "secret", there will be an under-reporting of the level of interest in the EF when the Bishops' reports are submitted to the Pope at the end of the first three years after the promulgation of Summorum Pontificum. It is essential, I think, that the Bishops include these "private" Masses in their reports; but will they do so?