Why would we say that? In the course of discussing the DoF position with Walsh we would have gone through all our targets and where we are in the process, just like any business does when recruiting a senior executive.
If it happens that we are close to closing a deal on the day he arrives it makes no difference to him, his role and future signings it's just the situation he is inheriting.
Koeman has probably identified targets, as he should have done as part of getting on with his job without a DoF - your sources may even be reporting back on early discussions with those targets - but I don't think anything will be wrapped up now without Walsh's say-so, and I don't see that vetting taking place within a few hours of him taking to his desk.
As for whether it makes a difference to him - of course it does. He's been brought in to co-ordinate transfers; if one is done without his input that takes a load of the potential transfer budget away from him, then that directly affects his job.
Also find it very implausible that Walsh has effectively been working for is for weeks without being signed, which is what it'd take for those early targets to be properly vetted by him and signed today.