I'd say she will, Heirflick. However, she spent a long period sidelined in the 90s when 461, 171, 4 and 85 were all bumbling about - at any one time, three of the four of them anyway. She is very useful in many ways, especially things like Santas, and crews are familiar with her, but main line speed especially tender first is a problem on things like long distance day trips and the May tour. There is much to be done with other engines, so she might be out for a while. 184, on the other hand, may not see steaming again - at any rate, for a very long time, as she requires little short of a total rebuild. In relation to 171 and 131, the cost of restoration of either - and in the case of 131, fabrication of many many missing parts - is astronomical. Work will proceed as funds and time permit, but as mentioned by others they will both be long term as a result.
As a general rule nowadays, given patterns of usage and the logistics of maintenance, repair and restoration, any steam engine can be considered to be in traffic for 6 to 7 years out of every ten. After each ten year period, even if they are currently in traffic, very major 10-year exams are required for insurance and health and safety purposes. This type of exam requires a boiler lift at least; itself producing a bill for the finance officer of the day to mull over. This applies to anything steam that the RPSI has, north or south, main line or Whitehead site; also anything on the DCDR.