Well, it is still worth to try if the "pending balance" is substantial, like maybe 50% of your deposit.
Yap it seems that it is a new requirement for their 5mbtc no deposit bonus, previously there was no such requirement as I was able to withdraw my winning from the 5mbtc bonus. Imo, the requirement is still reasonable enough and it is not really hard to achieve (wager 1x of the required deposit) but for sure if your pending balance is just too small then it does not really worth to deposit and risking your own 5mbtc. My suggestion if it is possible, continue playing with the winning amount first with a hope that you can have more balance before you make your own 5mbtc deposit.