isTrustedSignal/Context should return false when no trusted set has been defined

packages/@lwc/shared/src/__tests__/context.spec.ts

@@ -96,8 +96,8 @@ describe('context', () => {
             expect(isTrustedContext({})).toBe(false);
         });
 
-        it('should return true for all calls when trustedContexts is not set', () => {
-            expect(isTrustedContext({})).toBe(true);
+        it('should return false for all calls when trustedContexts is not set', () => {
+            expect(isTrustedContext({})).toBe(false);
         });
     });
 });

packages/@lwc/shared/src/__tests__/signals.spec.ts

@@ -53,8 +53,8 @@ describe('signals', () => {
             expect(isTrustedSignal({})).toBe(false);
         });
 
-        it('should return true for all calls when trustedSignals is not set', () => {
-            expect(isTrustedSignal({})).toBe(true);
+        it('should return false for all calls when trustedSignals is not set', () => {
+            expect(isTrustedSignal({})).toBe(false);
         });
     });
 });

packages/@lwc/shared/src/context.ts

@@ -47,15 +47,13 @@ export function setTrustedContextSet(context: WeakSet<object>) {
 }
 
 export function addTrustedContext(contextParticipant: object) {
-    // This should be a no-op when the trustedSignals set isn't set by runtime
+    // This should be a no-op when the trustedContext set isn't set by runtime
     trustedContext?.add(contextParticipant);
 }
 
 export function isTrustedContext(target: object): boolean {
     if (!trustedContext) {
-        // The runtime didn't set a trustedContext set
-        // this check should only be performed for runtimes that care about filtering context participants to track
-        return true;
+        return false;
     }
     return trustedContext.has(target);
 }

packages/@lwc/shared/src/signals.ts

@@ -21,10 +21,7 @@ export function addTrustedSignal(signal: object) {
 
 export function isTrustedSignal(target: object): boolean {
     if (!trustedSignals) {
-        // The runtime didn't set a trustedSignals set
-        // this check should only be performed for runtimes that care about filtering signals to track
-        // our default behavior should be to track all signals
-        return true;
+        return false;
     }
     return trustedSignals.has(target);
 }