Yes, Neander is referring specifically to millions of Replicants
It's important to remember Wallace's earlier monologue with Luv when he creates the Replicant who turned out to be a failed attempt at a fertile one:
He runs the SCALPEL’S dull edge under the Model’s CHIN to
raise it. Stills her when she again shivers.
NIANDER WALLACE
Every leap of civilization was built off
the back of a disposable workforce. We
lost our stomach for slaves. Unless...
engineered. And I can only make so many.
He runs the dull edge along the entire length of the Model.
NIANDER WALLACE (cont’d)
To make this I have to build from whole
cloth. Bit by bit and at great expense.
Shameful inefficiency, built into
Tyrell’s template. Tyrell.
He touches the Model’s abdomen at the navel.
NIANDER WALLACE (cont’d)
That barren pasture, empty and salted.
Right there. The dead space between the
stars. This the seat that we must change
for Heav’n.
With a swift motion he CUTS the Model across the ABDOMEN.
She stands for an uneasy moment as he continues:
NIANDER WALLACE (cont’d)
I cannot breed them. I have tried, so
help me. Tyrell’s final puzzle in
adamantine chains and penal Fire.
He drops the scalpel.
NIANDER WALLACE (cont’d)
We need more Replicants than can ever be
assembled. Millions so we can be
trillions. More. Worlds beyond worlds,
diamond shores. We could storm Eden and
retake her...
THE MODEL COLLAPSES.
![enter image description here](https://cdn.statically.io/img/i.sstatic.net/1tOUY.png)
Note that he specifically mentions how he has to 'create' them and refers to them as his 'angels'. He sees himself as a god and the Replicants his created children.
This is why when speaking with Deckard, he refers to the millions of Replicants as his 'children':
DECKARD
You don’t have children, do you?
NIANDER WALLACE
I have millions.
Deckard shakes his head. Laughs.
![enter image description here](https://cdn.statically.io/img/i.sstatic.net/tQlm5.png)