The coalition is quite serious since according to Mahathir there will be headquarter office of this group. Indonesia has been hinted by Mahathir as the potential place where headquarter will be based on. I think it is a good initiative to get Indonesia government have some enthusiasm in bringing the agenda forward. Malaysia is not a good place for the headquarter as it only have 60 % Muslim and the population is rather small but it will be remembered as the country who initiated the effort during Mahathir leadership. Mahathir will be replace soon by Anwar Ibrahim in 2020 so he want to make this coalition as fast as it can before he stepping down as Malaysian PM.
Don't mind me bro but if Mahatirs' vision for this block is his own than once he is gone either the work on it will be slowed , or die down completely , in order for Malaysia to take the lead its leadership needs to be consistent on what they want . Second If Malaysia elected a leader who later join the Saudi club that there will huge blow back to this block and it will die out . Now I am not saying it will happen I am just presenting it as a Possibility .
The coalition IMO then will start to initiate Muslim FTA where Muslim goods and services will have preference on each Muslim country and it will have to start from this 5 countries. In political front, IMO this 5 countries will strenghten the agenda to democratize Muslim nation further.
Thing is bro, that none of these Countries involved can ignore each other because all of these countries like Malaysia , Turkey , Qatar , Indonesia and Pakistan are rising economies and each one of them have a huge population so the potential for trade will always remain high, and if there is any country which miss the opportunity can always join later, we can not ignore a huge Muslim Population of west Africa .
The biggest dream of this coalition IMO is to bring Saudi and Iran together. If Saudi and Iran conflict can be solved so many conflict in Muslim world will likely be disappear and the coalition then can initiate peace process in Yemen, Afghanistan, and Syria.
Pakistan is already on to it, we share border with Iran hence we want to see a stable Iran, we already have a war torn Afghanistan and saw its effects on us , now what ever this new block can do will once again need Pakistan support in order to sit with KSA, cause we hold one of the largest Sunni Muslims, and KSA will eventually heed our advice on the matter .
Pakistan is stress over Kashmir issue, and the huge number of IA troops sitting there, it is natural for any country to be cautious when its enemies brings hundreds of thousands of its troops close to border, and constantly threatening to attack . We need world support over the issue, also we need world support to de-escalate things with India .
And beside all of that, the coalition IMO will please our Lord, Allah SWT and prophet Muhammad that we try to make unity among Muslim world and try to make solution on our current problem.
Allah will be Pleased when he see his people uniting under one Religion with no differences, the thing is we are just too divided along the racial lines ( including myself ) that we can not make a united front of Muslims and a Alliance like NATO, its just not possible in next couple of decades .
On Pakistan side IMO the club can try to make more preference on Pakistan goods and agriculture product to be sold in Turkey, Indonesia, Malaysia, and Qatar market. Making more contact between businessmen among the coalition members so that investment and channel among the members will get stronger. Kashmir issue will have more voice as well and Pakistan influence on OIC over Kashmir can be more strenghten.
Pakistan right now is stuck, no matter how much emotional Pakistani's curse its army or leadership the truth is that we are in a phase where we need to take every step with cautious , Pakistani economy is barely recovering, we have high tensions with India, Kashmir issue is boiling , Internal Politics is a mess, Hostile Afghanistan and Potential sleeper cells of Terrorists in Pakistan, Rising Tensions between Iran and KSA, Iran and USA . we have to look after our own as well, we don't want to be in any conflict until we have a stable economy and Indian War hysteria is down .