Underwhelming if true, tbf i really wish there was some other way or better options to go for but i guess this are the circumstances atm and there's not much we can do about it, hopefully he turns up for at least a half-decent season because we will need him to do well, there's no way he is not coming here as a starter, the figures involved and his mentality/personality clearly suggest that he would never accept to come here only as a rotation/depth role, yes, even as a 34/35yo, if there's someone dumb enough to be proposing it then be sure that's what we should expect.
I'd ask myself another question, what other semi-relevant CL contender would even realistically consider Dzeko as their main ST/CF in 2020? not even literally, but practically there are perhaps barelly a few that would even consider him for a depth role at this point, which again, it's hard to think that he would actually take it into consideration knowing that otherwise he is better off where he already is.