The Sigil is gone, Molly tiptoed through Harry's Tulips, he got a power up from Mr. Sunshine and his soul went on a walkabout in Ghost Story. If she's in there, she's well hidden. But I admire an optimist.
Making the Sigil go away is presumably easy for a Fallen; given that it was only a Shadow -- not an actual Fallen -- I'm guessing it was a "False Flag" planted to help the victim (Harry) feel guilty, and hopeless: already Marked, already Claimed, already on-file with a change-of-address to "Warmer Climes" (all a
lie, of course; but lies are how they roll Down There).
Molly's good, but a relative novice. She was losing mentally to Capiorcorpus, who was just a century or two old; I'm sure the Shadow of a Fallen is hidden from most mortal mind-magic; even a natural talent like Molly (maybe if she'd had another century's experience, it'd have been different? Or maybe not!). Note, for example -- a Fallen had just exerted mental influence to make Harry suicidal. That's a major invasion, fresh in his mind... and he calls on Molly to help him... and she didn't notice
anything.
Mr. Sunshine's powerup, I think, had several purposes. First, it's reward for resisting the Shadow so long; second,
Up There thinks that Harry's gonna to keep fighting the Outsiders, and wants the Starborn Wizard suitably equipped. Third -- and perhaps most importantly -- Harry now has a
tangible proof that the Divine
approves of him, of what he does, of how he does it.
Because we know that Harry having faith in himself and his magic is critical to his success; and that particular "attaboy" is particularly meaningful to him; he is
officially on the same team that Michael Carpenter is on, and Michael is "the best man Harry knows."
If it turns out that Harry does still have Lasciel's Shadow (and Lash is gone) that's gonna hit him in the morale really hard. Knowing he has Soulfire (Heaven's vote of confidence in him) could be a key asset in resisting a new assault on his independence.
Really: how often do you think Uriel's actions are a single-ply deep in complexity? I'm quite certain there are other layers that I haven't spotted; even if my "Lasciel's still there" theory turns out to be wrong.
Harry's soul *did* go walkabout, it's true. But he took everything with him on his little jaunt (except his living vitality), and brought it all back. Or, possibly, Lasciel stayed quiescent in his meat-brain, and when he woke back in his body, so did she.
(n.b. despite my arguing with you: the admiration is mutual!)
I on the other hand suggest she's hiding in plain sight.
"She" the Shadow, or Lasciel herself?
We're told that the Shadow -- all that's left of her (traces? some? most? all? we don't really have a clue, afaik) -- became Bonea.
However, I'm uncertain we've been told that by anyone both sufficiently-informed and sufficiently-unbiased that we can rely on that info; I consider it only a "working theory."
Or are you suggesting that Lasciel herself has found a new Host "in plain sight" ... i.e. with one of Harry's friends/acquaintences (maybe Lara? maybe one of the Alpha's? etc).