You are asking if you buy an older house next to a new community, will your home decrease in value when the new development is completed, right? The answer is: No. Especially if the new development includes new stores, increased walking paths and amenities that aren't present right now (*Starbucks, grocery stores, restaurants...etc).
Check out this link:
Also, there are always new homes or new construction wherever you go. It depends on your individual house. If you keep up with repairs and make sure your home is well-maintained, then you have nothing to worry about. If you let it fall apart while everyone around you makes improvements...then, yes. Yes, your home price will suffer.
Hope that helps! Happy House-Hunting!!!
Janeene & #TeamSilvester