Pat the chicken breasts dry with paper towels.
Place the chicken in the Instant Pot and sprinkle the ranch seasoning over it; add 1/2 cup water and stir gently to distribute the seasoning.
Close the lid and seal the valve. Set the Instant Pot to Manual/High Pressure for 15 minutes. Allow natural release for 5 minutes, then quick-release any remaining pressure and carefully open the lid.
Transfer the cooked chicken to a cutting board or bowl and shred it with two forks.
Add the shredded chicken back to the Instant Pot along with the cream cheese (cut into pieces if desired), diced green chiles, condensed cream of chicken soup, chicken broth, and egg noodles. Stir to combine and distribute the cream cheese.
Close the lid and seal the valve again. Set the Instant Pot to Manual/High Pressure for 3 minutes.
When the cook cycle finishes, allow the Instant Pot to natural release (about 10 minutes) before opening the valve and removing the lid.
Stir the noodles and sauce until the cream cheese is fully incorporated; season with salt and pepper to taste if needed, then serve.