This is a very good development and I believe WK is behind it - the guy is the only professional either side among ........ you know

I think, the ultimate target for PAK/PCB should be to bring Test cricket in PAK. A Test tour comes with two challenges - 1. It's a 5 days game means, even 2 Tests tour will require 15 days intense environments both on & off the field. 2. SRL agreed, but I don't think other teams will agree to play Test within 48-72 hours of landing in PAK and without any practice game, means PCB will have to arrange may be two, at least one 3 days game with similar preparation (but absolute no monetary return).
I think, it's utmost important to host both Tests is PAK, may be even at a single (Karachi) venue (with the practice game as well), and compromise everything else. PAK is already arranging T20s & ODIs at home, PSL is also scheduled entirely in PAK, therefore hosting BD for few LO games is just a side wise shift, doesn't hold the gain PCB achieved by bringing SRL for Test series. If PSL ends successfully without much issues, I believe next year PAK can bring SENA countries for T20 & ODI in PAK - one reason is restored credibility but the main reason is next two ICC events after 2020 WC in AUS (a 3rd mega event could the the proposed ODI tournament) are scheduled in India and teams would like the opportunity to acclimatize as much as possible in South Asian condition. But, Test cricket is different issue - there is not much at PCB's hand (as a bargain chip), therefore they have to move by inch to ultimate goal.
In that regard, I think not only one Test in BD, PCB's proposal should be to play both Tests (why not three?) in PAK (may be even later sometimes in August/SEP, if it's already to late) and right not crack a deal to play several LO games in BD during IPL period as a revenue sharing model. It's not about who is host, rather BCB will pay PCB a fixed amount as guarantee money (regardless of their income, it's given) and a percentage of net earnings. There is an issue of broadcasting rights, therefore PCB/BCB can't arrange something as joint venture - it'll always be like one Board earns the media rights, other one can be benefited in cash payment, regardless of the venue. At the end of the day, money ever becomes too much!!!!
I am actually more concerned (disturbed is probably better wording here), that both BD & PAK players will be sitting idle for 10 weeks of IPL and this is what makes our players vulnerable to illegal bookies & corrupt crickets in middle-east. Last AFG-BD-ZIM series was hit in BD and PAK is still one of the most popular team - it's easily possible to arrange 3 Tests, 6 ODIs and 3 T20Is during that period and it'll be hit. In fact, BD-PAK Test series will be financially positive individually (not as part of a package with LOs attached) - last time over 50K paid crowd came to watch all 4 BD-ENG/AUS Test in both venues.
PS: I can see this latest update is few hours old but hardly any post here - I probably can understand the reason. Guys, there is no winner here and no one should feel bitter that PCB is trying to negotiate - the ultimate target is to bring Test cricket in PAK. I myself is quite ashamed with this tool Papon using his power & position to settle scores (& we'll have to pay for it sometimes in future - what goes round comes back), but he also has a valid reason for his stand and both boards have to move forward for their respective position........ same goes for the fans as well. At the end of the day - neither can improve without playing the thing on field.