I think, Test & ODI will be much closer than what most predicting.
In ODI, PAK has improved lot from the team that lost 3-0, and it should improve further with Sarfu's Captaincy. While, even an average team with all 11 players reaching peak at one time can do miracles if couple of world class players back them - just like SRL won the WC, we had a purple patch in 2015, but maintaining that level is tough for any team. Still, it'll be very close ODI between PAK-BD, almost everywhere.
In Test, BD's batting is technically better that PAK & everyone is excellent spin player. Not sure why people are thinking in UAE roads PAK will take 20 wickets against this batting line up. I see it other way - on standard UAE roads, it'll take a collapse for us to lose 20 wickets - probably most Test will end in draws. On rank turners, the bowling gap reduces significantly because Sakib, Miraj, Taijul backed by Mustafiz on those wickets will trouble PAK equally, if not more. If all 3 Tests brings result in 4 days, it won't be 3-0 PAK for sure, could be even 2-1 for BD. Only wicket where PAK has a significant advantage is the type of wicket none of PCB farmers has any clue of how to prepare - PAK will run through BD on the wicket that IND-PAK Asia Cup T20 was played, but it's 3 clouds above Aga Zahid's level & it's not possible to prepare in UAE either. May be, PAK'll clean sweep in Test series only in UK.