Jewish Action, Summer 2005 edition, has a "What's the truth about..." column by Rabbi Dr. Ari Z. Zivotofsky on not meeting for the week preceding the wedding. His main point is the lack of old sources for this custom, but he does cite several newer sources and the reasons they give. See there for the details, but the reasons and post-facto rationales offered are:
- to avoid dam chimud (which he cites strong arguments against as a reason for the custom, so I'll ignore it);
- to prevent discussions that will lead to strife (Rabbi E.M.M. Shach; Rabbi Y.S. Elyashiv, who therefore bans communication by telephone also);
- to allow the couple time apart for introspection (Rabbi Binyamin Forst);
- to heighten excitement (unsourced); and
- to prevent premarital relations (unsourced).
All the reasons except the last seem to me to apply equally to phone, text, or other conversation as well as to face-to-face conversation. (Perhaps not to communication via a messenger, however; see also the comments to this answer.) And as Rabbi Zivotofsky notes, the last reason should apply only to being alone together, not to simply meeting.
So if the custom exists at all — and see the article for reasons it does not and for rabbis quoted as saying it does not (but also some who defended it) — then my impression (only my impression!) is that all the means of communication asked about (again, possibly except communication via a messenger) have the same rule as face-to-face communication.
(Looking at the fiancé(e)'s Facebook page is not communication and seems not to IMO be cause for the above-listed concerns. Nor do we see that in years past a marrying couple were told not to read each other's publicly posted notices AFAIK.)
As always, consult your rabbi for a practical ruling.