This conveniently ignores that Cashu is custodial, so it’s not bitcoin, so it’s not adoption. This is also what nostr:npub12rv5lskctqxxs2c8rf2zlzc7xx3qpvzs3w4etgemauy9thegr43sf485vg used to say iirc: cashu != bitcoin and cashu isn’t for scaling bitcoin.
It also ignores that a product like Signal is used by millions of user, most who probably don’t like bitcoin. I’m pretty sure it’s not the mission of Signal to push bitcoin adoption. They will probably get a lot of backlash if they would even consider this, without even mentioning that it’s not even bitcoin but suggesting to use custodial trusted third parties. This will look like a joke in MSM.