When I first started playing a month ago I had 1 special order. After having completed it I have yet to receive another. The daily orders, until a few weeks ago, usually had 1 order that would unlock a special weapon, I haven't had any in a while and ever since the daily orders have been identical every day.
Contracts are the ones that let you do a contract and receive a specific weapon if you complete it - Daily Orders never have, unless you could weapons you get in supply drops as "unlocking a special weapon". As far as the "Special Orders", they've come out and said that they've had bugs in the special orders, so they do them every now-and-then to test it out, I guess? But it's been like that for awhile, where we'll get one special order, normally for "complete 150 matches" to get like 5 supply drops or something like that....but then they won't have another one for a few months.