Néih hóu Tse Wai Shun Jerry, welcome to Flyertalk and to the BA Board, it's good to see you here and I hope we will see plenty more of you on this forum.
MNL was certainly under BA's radar, but there were all sorts of aspects that have meant that so far it hasn't returned to the BA schedule yet. BA used to run to MNL 4 days a week on 747 jumbo jets, with a stopover in Hong Kong (so BA31 and BA32, which still operates to HKG only). This is going back 20 years ago, more recently the rumours seemed to pitch MNL in a stopover with CGK/Jakarta, to get around some of the operational hurdles.
TPE seems to be an odd omission from BA's schedules, but the issue there is that a lot of local competition means that it's unlikely to be that profitable for BA. Again it features in the rumour list recently, but unfortunately I doubt we will see it in the near future. Going back to the past, it used to be a tag on service to BA25 and BA26. three days a week and again via HKG, but operated by British Asia Airways, which sadly is no longer with us.