I did hear yesterday evening that SEN did actually declare itself unable to accept additional diversions; the only one I know of suggested as being affected was a LH EMB-190.
I used to get very annoyed that SEN doesn't these days try very hard to accept the maximum number possible at any given time, but I suppose it makes only a minimal difference to profitability in reality. It's really the apparent 'jobsworth' attitude of their Operations department in this context which I find disappointing.
Of the couple of BA diversions they received today one was in fact an aircraft which had diverted to SEN yesterday which attempted to position back to LCY only to have to carry out two go-arounds and then return to SEN. Three Cityjet RJs diverted to STN today, presumably as the crosswind at SEN was as bad as that at LCY at the time.