I am sure there is no future for "Metre gauge railways". They were a feature of an increasingly distant past. A few still continue but most have been discontinued. I have made a lot of use of the metre gauge system in East Africa, and have found them quite useful, but the trend even there is to replace them with Standard gauge lines, as can be seen in Kenya. The new standard gauge lines will have greater capacity and faster line speed, which will be very useful. The metre gauge trains needed sleeping cars for the higher classes, but the faster SG trains will not need them.
When they were built in Europe the aim was to spend less on investment in areas of low demand. The same was true of Africa and other colonial areas. The decision was made to spend less, but in retrospect we can see that this was an unfortunate policy. In Europe the early lines did not have to face road competition but their slower speeds put them at a disadvantage nowadays. In Europe the metre gauge lines were built in areas which had less demand for transport. In almost all cases the development of efficient road vehicles has rendered them uncompetitive. Most of the lines you are describing here are distant memories.