The 777 accident did spike visitors - massively.
This was set against a background of increased volumes for the site that were already requiring the making of plans for server upgrades.
There are two kinds of PPRuNe reader - the registered kind that log-in and visitors that are read only. Visitors will often outnumber registered users at any given time.
I cannot offer timescales or even precise details, but can offer you the knowledge that plans are being progressed to improve the situation.