Without the reveal, I had no clue what the theme might be. So let's start with that:
69-Across. Poker request, and a literal hint to what's hidden in the answers to the starred clues : ANTE UP.
Aha! All of the starred clues were "down" answers. And you can find ANTE climbing "up" the grid in each one, like 3-Down. *Cold War fleet :
S
O
V
I
E
T
N
A
V
Y.
10-Down. *Honey and Boo Boo, e.g. : PET NAMES. I was thinking along the line of bears!
27-Down. *Wings eaters' aids : WET-NAPS.
31-Down. *Austroasiatic language : VIETNAMESE. The language family has nothing to do with Austria. In Latin "austro" means "south."
39-Down. *Prepare for a bath : GET NAKED. And then?
Across
1. GM car buyer's option : ONSTAR. Love it when I fill in 1A immediately.
7. Make more powerful, with "up" : SOUP. Anyone else want "beef"?
11. White lie : FIB.
14. Illinois River city : PEORIA.
15. "Gift From the Sea" author __ Morrow Lindbergh : ANNE.
16. Milk : USE.
17. Go back : REVERT.
18. Not quite closed behind you : LEFT AJAR.
20. Foreman foe : ALI.
21. She played TV's Maude : BEA. Arthur.
23. Food processor job : MINCING.
24. Serengeti scavenger : HYENA.
26. Try to hit : SWAT AT.
28. Turn to the right, say? : TIGHTEN. "Right-y tight-y, left-y loose-y."
30. Chess activity : MOVES.
34. Tailless cat : MANX. They are named after the Isle of Man.
36. Poetry or painting : ART.
37. Published in installments : SERIAL.
38. George's lyrical brother : IRA. The brothers Gershwin.
39. Strangers' exchanges : GLANCES. As good an excuse as I will ever get to link Ol' Blue Eyes. 2:04
41. Important time period : ERA.
42. Protective embankments : LEVEES.
44. "So it was you!" : AHA!
45. Work meas. : FT. LB. Foot pound.
46. "Cat got your tongue?" : SAY IT.
47. East Lansing athlete : SPARTAN.
49. Banded rock : GNEISS.
51. Easy __ : AS ABC. Had to check perps before deciding on "pie" or ABC.
54. Pub pick : PALE ALE.
57. Jan. honoree : MLK. Martin Luther King.
59. Stain : MAR.
60. Dancing style that went viral on YouTube in 2013 : TWERKING.
62. Mocha resident : YEMENI.
64. Studio creation : SET.
65. Poet __ St. Vincent Millay : EDNA.
66. Cooks slowly : ROASTS.
67. Crown installer: Abbr. : DDS. AHA! Saturday we had DMD. DDS is more Thursday-friendly, I guess.
68. Poker request : DEAL.
Down
1. Angel Network charity founder : OPRAH.
2. Hockey Hall of Famer Cam : NEELY. Gimme - he played for the Boston Bruins, and is now president of that organization.
4. Square root of nove : TRE. Italian "three."
5. Auto safety device : AIRBAG.
6. Give a star, perhaps : RATE.
7. See 61-Down : SAL. 61-Down. With 7-Down, Hayworth title role, with "My" : GAL. From 1942.
8. Like some bands : ONE MAN.
9. Out of shape : UNFIT.
11. McIntosh alternative : FUJI. Duh! The edible apples, not computers.
12. "This __ outrage!" : IS AN.
13. Baffin Bay sight : BERG.
19. Matthew Fox or Peter Coyote : ACTOR. They sound like they could be in the book "Wind in the Willows," along with Mr. Toad and Mr. Badger.
22. Latin stars : ASTRA.
25. Put the kibosh on : NIX.
29. Dutch portraitist Frans : HALS. A master of portraiture.
32. Countess' husband : EARL.
33. Big chunk : SLAB.
34. Wire units : MILS.
35. House painter's calculation : AREA.
37. Char : SEAR.
40. Great divide : CHASM.
43. Peak in an Eastwood film : EIGER. "The Eiger Sanction." 1975.
45. Scale fourths : FAs. After do, re and mi. Want to learn all about solmization?
47. Earth pigment : SIENNA.
48. Tangle with : TAKE ON.
50. Say "prob'ly," say : ELIDE.
52. African language group : BANTU.
53. Like new bills : CRISP.
54. VA concern : PTSD. Post Traumatic Stress Disorder.
55. Gobsmacked : AWED. Great word, "gobsmacked."
56. Al Green's "__ Stay Together" : LET'S. Great classic love song, but I already linked one today...
58. Harp constellation : LYRA.
63. Yoga __ : MAT. Ommmmm....
...mmmmMarti