You're conclusion is right but I don't agree with the reasoning if this is indeed the club's view. If Dele Alli were coming through at MK Dons now we'd probably not go in for him and that's bad policy. No one expected Dele to make the jump up so quickly and so well but he did and £5m looks a bargain. This season was his first "poor" season but it's relative to the high standards he set so early.
If we were to buy Maddison now we're talking a fee north of £40m. Ditto with Brooks. 12 months ago they cost £30m between them. Both would have got into our team on the basis of the seasons they had, coupled with our out of form / lack of options during the season too. We can't miss out on these players.
Personally I don't think it's so much the clubs view, as an obvious concern to a potential signee.
From another perspective; we just spent £40m on Dav and even he's struggling to keep that pathway open whilst he makes a few inevitable errors whilst he comes of age. We could go out and spend 30-40 mill each on the above and/or Sessengon; who's to say things will be any smoother for them? Meanwhile we'd have blown circa 100m, yet still have pressing need for improvements to our first XI.
It's a quandary.