diff --git a/.chloggen/not-sure-understand.yaml b/.chloggen/not-sure-understand.yaml
new file mode 100644
index 0000000000000..cf6417b957c43
--- /dev/null
+++ b/.chloggen/not-sure-understand.yaml
@@ -0,0 +1,27 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: breaking
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: pkg/stanza
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Remove deprecated `flush.WithPeriod`.
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [37784]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: [api]
diff --git a/pkg/stanza/fileconsumer/internal/reader/factory.go b/pkg/stanza/fileconsumer/internal/reader/factory.go
index 170df57377c62..a20a92911ae04 100644
--- a/pkg/stanza/fileconsumer/internal/reader/factory.go
+++ b/pkg/stanza/fileconsumer/internal/reader/factory.go
@@ -59,20 +59,15 @@ func (f *Factory) NewReader(file *os.File, fp *fingerprint.Fingerprint) (*Reader
 	m := &Metadata{
 		Fingerprint:    fp,
 		FileAttributes: attributes,
-		TokenLenState:  &tokenlen.State{},
-	}
-	if f.FlushTimeout > 0 {
-		m.FlushState = &flush.State{LastDataChange: time.Now()}
+		TokenLenState:  tokenlen.State{},
+		FlushState: flush.State{
+			LastDataChange: time.Now(),
+		},
 	}
 	return f.NewReaderFromMetadata(file, m)
 }
 
 func (f *Factory) NewReaderFromMetadata(file *os.File, m *Metadata) (r *Reader, err error) {
-	// Ensure TokenLenState is initialized
-	if m.TokenLenState == nil {
-		m.TokenLenState = &tokenlen.State{}
-	}
-
 	r = &Reader{
 		Metadata:             m,
 		set:                  f.TelemetrySettings,
diff --git a/pkg/stanza/fileconsumer/internal/reader/reader.go b/pkg/stanza/fileconsumer/internal/reader/reader.go
index 4cd3e910c2a95..f3783aeb7274d 100644
--- a/pkg/stanza/fileconsumer/internal/reader/reader.go
+++ b/pkg/stanza/fileconsumer/internal/reader/reader.go
@@ -31,8 +31,8 @@ type Metadata struct {
 	RecordNum       int64
 	FileAttributes  map[string]any
 	HeaderFinalized bool
-	FlushState      *flush.State
-	TokenLenState   *tokenlen.State
+	FlushState      flush.State
+	TokenLenState   tokenlen.State
 }
 
 // Reader manages a single file
diff --git a/pkg/stanza/flush/flush.go b/pkg/stanza/flush/flush.go
index 1dfa93f13a21c..62c827bafb8a2 100644
--- a/pkg/stanza/flush/flush.go
+++ b/pkg/stanza/flush/flush.go
@@ -61,9 +61,3 @@ func (s *State) Func(splitFunc bufio.SplitFunc, period time.Duration) bufio.Spli
 		return 0, nil, nil
 	}
 }
-
-// Deprecated: [v0.88.0] Use WithFunc instead.
-func WithPeriod(splitFunc bufio.SplitFunc, period time.Duration) bufio.SplitFunc {
-	s := &State{LastDataChange: internaltime.Now()}
-	return s.Func(splitFunc, period)
-}
diff --git a/pkg/stanza/flush/flush_test.go b/pkg/stanza/flush/flush_test.go
index e8bb369ac77c2..5bd9832598587 100644
--- a/pkg/stanza/flush/flush_test.go
+++ b/pkg/stanza/flush/flush_test.go
@@ -41,8 +41,6 @@ func TestNewlineSplitFunc(t *testing.T) {
 	}
 
 	for _, tc := range testCases {
-		t.Run(tc.name+"/WithPeriod", splittest.New(WithPeriod(tc.baseFunc, tc.flushPeriod), tc.input, tc.steps...))
-
 		previousState := &State{LastDataChange: time.Now()}
 		t.Run(tc.name+"/Func", splittest.New(previousState.Func(tc.baseFunc, tc.flushPeriod), tc.input, tc.steps...))
 	}